diff --git a/cpp/tensorrt_llm/nanobind/batch_manager/bindings.cpp b/cpp/tensorrt_llm/nanobind/batch_manager/bindings.cpp
index fb0153f5ff8..151b33b1195 100644
--- a/cpp/tensorrt_llm/nanobind/batch_manager/bindings.cpp
+++ b/cpp/tensorrt_llm/nanobind/batch_manager/bindings.cpp
@@ -57,8 +57,8 @@ void initBindings(nb::module_& m)
     using GenLlmReq = tb::GenericLlmRequest<runtime::ITensor::SharedPtr>;
 
     // Create and register exceptions in module scope
-    nb::exception<tb::PeftTaskNotCachedException>(m, "PeftTaskNotCachedException");
-    nb::exception<tr::LoraCacheFullException>(m, "LoraCacheFullException");
+    static nb::object peft_exc = nb::exception<tb::PeftTaskNotCachedException>(m, "PeftTaskNotCachedException");
+    static nb::object lora_exc = nb::exception<tr::LoraCacheFullException>(m, "LoraCacheFullException");
 
     // Register with no captures
     nb::register_exception_translator(
@@ -71,11 +71,11 @@ void initBindings(nb::module_& m)
             }
             catch (const tb::PeftTaskNotCachedException& e)
             {
-                PyErr_SetString(nb::type<tb::PeftTaskNotCachedException>().ptr(), e.what());
+                PyErr_SetString(peft_exc.ptr(), e.what());
             }
             catch (const tr::LoraCacheFullException& e)
             {
-                PyErr_SetString(nb::type<tr::LoraCacheFullException>().ptr(), e.what());
+                PyErr_SetString(lora_exc.ptr(), e.what());
             }
         });
 
diff --git a/cpp/tensorrt_llm/nanobind/executor/request.cpp b/cpp/tensorrt_llm/nanobind/executor/request.cpp
index e2ed1fb2d19..80b9b52bd9d 100644
--- a/cpp/tensorrt_llm/nanobind/executor/request.cpp
+++ b/cpp/tensorrt_llm/nanobind/executor/request.cpp
@@ -210,10 +210,21 @@ void initRequestBindings(nb::module_& m)
             nb::cast<std::optional<std::vector<tle::AdditionalModelOutput>>>(state[6]));
     };
     nb::class_<tle::OutputConfig>(m, "OutputConfig")
-        .def(nb::init<bool, bool, bool, bool, bool, bool, std::optional<std::vector<tle::AdditionalModelOutput>>>(),
-            nb::arg("return_log_probs").none() = false, nb::arg("return_context_logits") = false,
-            nb::arg("return_generation_logits") = false, nb::arg("exclude_input_from_output") = false,
-            nb::arg("return_encoder_output") = false, nb::arg("return_perf_metrics") = false,
+        .def(
+            "__init__",
+            [](tle::OutputConfig& self, std::optional<bool> return_log_probs, std::optional<bool> return_context_logits,
+                std::optional<bool> return_generation_logits, std::optional<bool> exclude_input_from_output,
+                std::optional<bool> return_encoder_output, std::optional<bool> return_perf_metrics,
+                std::optional<std::vector<tle::AdditionalModelOutput>> additional_model_outputs)
+            {
+                new (&self) tle::OutputConfig(return_log_probs.value_or(false), return_context_logits.value_or(false),
+                    return_generation_logits.value_or(false), exclude_input_from_output.value_or(false),
+                    return_encoder_output.value_or(false), return_perf_metrics.value_or(false),
+                    additional_model_outputs);
+            },
+            nb::arg("return_log_probs") = nb::none(), nb::arg("return_context_logits") = nb::none(),
+            nb::arg("return_generation_logits") = nb::none(), nb::arg("exclude_input_from_output") = nb::none(),
+            nb::arg("return_encoder_output") = nb::none(), nb::arg("return_perf_metrics") = nb::none(),
             nb::arg("additional_model_outputs") = nb::none())
         .def_rw("return_log_probs", &tle::OutputConfig::returnLogProbs)
         .def_rw("return_context_logits", &tle::OutputConfig::returnContextLogits)
diff --git a/cpp/tensorrt_llm/pybind/executor/executorConfig.cpp b/cpp/tensorrt_llm/pybind/executor/executorConfig.cpp
index 1153ca13a8e..87f32635866 100644
--- a/cpp/tensorrt_llm/pybind/executor/executorConfig.cpp
+++ b/cpp/tensorrt_llm/pybind/executor/executorConfig.cpp
@@ -424,7 +424,7 @@ void initConfigBindings(pybind11::module_& m)
         .value("MPI", tle::CacheTransceiverConfig::BackendType::MPI)
         .value("UCX", tle::CacheTransceiverConfig::BackendType::UCX)
         .value("NIXL", tle::CacheTransceiverConfig::BackendType::NIXL)
-        .def(py::init(
+        .def("from_string",
             [](std::string const& str)
             {
                 if (str == "DEFAULT" || str == "default")
@@ -436,9 +436,7 @@ void initConfigBindings(pybind11::module_& m)
                 if (str == "NIXL" || str == "nixl")
                     return tle::CacheTransceiverConfig::BackendType::NIXL;
                 throw std::runtime_error("Invalid backend type: " + str);
-            }));
-
-    py::implicitly_convertible<std::string, tle::CacheTransceiverConfig::BackendType>();
+            });
 
     py::class_<tle::CacheTransceiverConfig>(m, "CacheTransceiverConfig")
         .def(py::init<std::optional<tle::CacheTransceiverConfig::BackendType>, std::optional<size_t>>(),
diff --git a/tensorrt_llm/llmapi/llm_args.py b/tensorrt_llm/llmapi/llm_args.py
index 125a652d800..6614391b452 100644
--- a/tensorrt_llm/llmapi/llm_args.py
+++ b/tensorrt_llm/llmapi/llm_args.py
@@ -30,6 +30,7 @@
 # isort: off
 from ..bindings.executor import (
                                  BatchingType as _BatchingType,
+                                 CacheTransceiverBackendType as _CacheTransceiverBackendType,
                                  CacheTransceiverConfig as _CacheTransceiverConfig,
                                  CapacitySchedulerPolicy as _CapacitySchedulerPolicy,
                                  ContextChunkingPolicy as _ContextChunkingPolicy,
@@ -871,7 +872,7 @@ class CacheTransceiverConfig(BaseModel, PybindMirror):
 
     def _to_pybind(self):
         return _CacheTransceiverConfig(
-            backend=self.backend,
+            backend=_CacheTransceiverBackendType.from_string(self.backend),
             max_tokens_in_buffer=self.max_tokens_in_buffer)
 
 
diff --git a/tensorrt_llm/serve/openai_protocol.py b/tensorrt_llm/serve/openai_protocol.py
index 84594cd473f..4a6545beef9 100644
--- a/tensorrt_llm/serve/openai_protocol.py
+++ b/tensorrt_llm/serve/openai_protocol.py
@@ -252,7 +252,7 @@ def to_sampling_params(self) -> SamplingParams:
             add_special_tokens=self.add_special_tokens,
 
             # TODO: migrate to use logprobs and prompt_logprobs
-            _return_log_probs=self.logprobs,
+            _return_log_probs=bool(self.logprobs),
         )
         return sampling_params
 
@@ -543,7 +543,7 @@ def to_sampling_params(self) -> SamplingParams:
             add_special_tokens=self.add_special_tokens,
 
             # TODO: migrate to use logprobs and prompt_logprobs
-            _return_log_probs=self.logprobs,
+            _return_log_probs=bool(self.logprobs),
         )
         return sampling_params