Rip,
try loading those libraries and making an archive file of the building. You can then extract the library of this file - it will be pared down to only the parts you're using. That should load faster.
The one caveat will be Macros called from the older parts. If they don't show up, you'll have to add the macros to your library manually.
Think Like a Spec Writer
MacBook M4Pro
AC4.55 through 29 / AC29.0.2 USA
Rhino 8.26 Mac
MacOS Tahoe 26.2