Here’s a list of the projects that have been suggested so far:
It doesn’t look like any of these support
BufferGeometry currently (unless I missed something).
@3DFish, I’d say your best bet is to ask on the repos for those projects, and see whether the owners would consider converting them to use
BufferGeometry. If you offer them a small fee they may be receptive, or they may even do it for free.
If that doesn’t work out, I would put the conversion of
BufferGeometry in your app on the backburner for a month or so and see if there are any further developments. If not, then you will need to pay someone to convert one of these libraries.