From what I’ve seen you might be able to switch between different scriptable render pipelines, but not to or from BiRP.
Maaaybe Unity 6 with better cross RP support might work, but I doubt it.
Maybe it is not 100% clear in that docs page, but this sentences hints to that “You can create multiple Render Pipeline Assets that use the same render pipeline, but with different configurations”
What is your use case? We recently gave a talk about transitioning from Built-In to URP at Unite Barcelona. Maybe this is also interesting for you: https://youtu.be/S1xG9Byf0Go?si=Ka5QpR1BpbReaYxn