diff --git a/lite_bootstrap/bootstrappers/fastapi_bootstrapper.py b/lite_bootstrap/bootstrappers/fastapi_bootstrapper.py
index 838e6a0..39a371d 100644
--- a/lite_bootstrap/bootstrappers/fastapi_bootstrapper.py
+++ b/lite_bootstrap/bootstrappers/fastapi_bootstrapper.py
@@ -112,14 +112,6 @@ def bootstrap(self) -> None:
 class FastAPIOpenTelemetryInstrument(OpenTelemetryInstrument):
     bootstrap_config: FastAPIConfig
 
-    def _build_excluded_urls(self) -> set[str]:
-        excluded_urls = set(self.bootstrap_config.opentelemetry_excluded_urls)
-        excluded_urls.add(self.bootstrap_config.prometheus_metrics_path)
-        if not self.bootstrap_config.opentelemetry_generate_health_check_spans:
-            excluded_urls.add(self.bootstrap_config.health_checks_path)
-
-        return excluded_urls
-
     def bootstrap(self) -> None:
         super().bootstrap()
         FastAPIInstrumentor.instrument_app(
diff --git a/lite_bootstrap/bootstrappers/litestar_bootstrapper.py b/lite_bootstrap/bootstrappers/litestar_bootstrapper.py
index 7a026d9..dc381e1 100644
--- a/lite_bootstrap/bootstrappers/litestar_bootstrapper.py
+++ b/lite_bootstrap/bootstrappers/litestar_bootstrapper.py
@@ -76,6 +76,8 @@ class LitestarOpenTelemetryInstrumentationMiddleware(ASGIMiddleware):
         def __init__(self, tracer_provider: "TracerProvider", excluded_urls: set[str]) -> None:
             self._tracer_provider = tracer_provider
             self._excluded_urls = ",".join(excluded_urls)
+            # Cache keyed by id(next_app); Litestar's ASGI app instances are stable for
+            # the middleware lifetime, so id-reuse-after-GC isn't a concern.
             self._otel_apps: dict[int, ASGIApp] = {}
 
         async def handle(
@@ -178,14 +180,6 @@ def bootstrap(self) -> None:
 class LitestarOpenTelemetryInstrument(OpenTelemetryInstrument):
     bootstrap_config: LitestarConfig
 
-    def _build_excluded_urls(self) -> set[str]:
-        excluded_urls = set(self.bootstrap_config.opentelemetry_excluded_urls)
-        excluded_urls.add(self.bootstrap_config.prometheus_metrics_path)
-        if not self.bootstrap_config.opentelemetry_generate_health_check_spans:
-            excluded_urls.add(self.bootstrap_config.health_checks_path)
-
-        return excluded_urls
-
     def bootstrap(self) -> None:
         super().bootstrap()
         self.bootstrap_config.application_config.middleware.append(
diff --git a/lite_bootstrap/instruments/opentelemetry_instrument.py b/lite_bootstrap/instruments/opentelemetry_instrument.py
index 1e7eeda..cf4d8f9 100644
--- a/lite_bootstrap/instruments/opentelemetry_instrument.py
+++ b/lite_bootstrap/instruments/opentelemetry_instrument.py
@@ -23,7 +23,7 @@
 
 
 def _format_span(readable_span: "ReadableSpan") -> str:
-    return typing.cast("str", readable_span.to_json(indent=None)) + os.linesep
+    return typing.cast("str", readable_span.to_json(indent=None)) + "\n"
 
 
 @dataclasses.dataclass(kw_only=True, slots=True, frozen=True)
@@ -92,6 +92,17 @@ def is_ready(self) -> bool:
     def check_dependencies() -> bool:
         return import_checker.is_opentelemetry_installed
 
+    def _build_excluded_urls(self) -> set[str]:
+        excluded_urls: set[str] = set(getattr(self.bootstrap_config, "opentelemetry_excluded_urls", []))
+        prometheus_path = getattr(self.bootstrap_config, "prometheus_metrics_path", None)
+        if prometheus_path:
+            excluded_urls.add(prometheus_path)
+        if not self.bootstrap_config.opentelemetry_generate_health_check_spans:
+            health_path = getattr(self.bootstrap_config, "health_checks_path", None)
+            if health_path:
+                excluded_urls.add(health_path)
+        return excluded_urls
+
     def bootstrap(self) -> None:
         logging.getLogger("opentelemetry.instrumentation.instrumentor").disabled = True
         logging.getLogger("opentelemetry.trace").disabled = True