Multiple calls to UseOwin is discouraged?

[oconnor0]

In https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/fundamentals/owin.md, there is a comment that says:

Note:
Multiple calls to UseOwin is discouraged for performance reasons. OWIN components will operate best if grouped together.

Does this mean that the following code is not a good idea? If so, why and what should it be instead? It's not obvious to me that this would be slower than some other structure, but maybe the comment is referring to something else.

app.Map("/a", a => a.UseOwin(pipeline => pipeline(next => HandleA)));
app.Map("/b", a => a.UseOwin(pipeline => pipeline(next => HandleB)));

[reduanul-islam]

From my understanding, the recommendation is about minimizing the number of ASP.NET Core ↔ OWIN pipeline transitions, not about avoiding Map itself.

In your example:

app.Map("/a", branch =>
{
    branch.UseOwin(pipeline => pipeline(next => HandleA));
});

app.Map("/b", branch =>
{
    branch.UseOwin(pipeline => pipeline(next => HandleB));
});

each branch creates its own OWIN adapter, but only requests matching that specific path will execute that branch. Functionally, this looks perfectly valid.

I interpreted the documentation note as a general performance recommendation for applications that register many OWIN components. When possible, grouping related OWIN middleware into a single UseOwin call avoids creating multiple adapter boundaries.

That said, for isolated route branches like this, I would expect the performance impact to be very small. It would be helpful if the documentation clarified whether this guidance is intended only for multiple UseOwin calls in the same pipeline or if it also applies to separate Map branches like the example above.