INot sure how you're binding TRPC to Express, but most likely as a middleware, and it probably doesn't have a specific path. You should be able to overwrite the span name possibly with e.g. an trpc middleware.
I@patrickj7332 Been working on adding OTEL Traces + Logging to my TRPC service on cloudflare workers, it's pretty nice, found this just to see if any packages or something exists for adding TRPC specific spans to the traces but doesn't seem so, so added some basic stuff myself, primarily wrote a trpc middleware that makes sure that each procedure is in it's own span so that batched requests are visualized properly.
I@PatrickJ there's an open telemetry library in the discord of Cloudflare, other than that the middleware is pretty simple, I've a pretty busy weeks ahead but I'll try to share something soon, if I don't feel free to DM me to remind me 