>> I do not understand the question. What needs formalization?

Oh, and the yearly stable releases (suggested for Scheme Live) would
still be a good idea IMHO. So any code/spec can change at any time, but
once a year, we cut a stable release of the interface at that point.
People who are interested in long term stability can continue to
maintain implementation(s) of that interface. That would really be the
only formal thing needed.

If work started before summer 2021, we could release the first stable
spec around the new year, for example. Could be done in the OpenBSD
manner where release dates are constant and known in advance, and before
release people settle down to clean up the codebase a bit so that a good
release can be cut from whatever things are ready. This model has worked
extremely well for OpenBSD and may be the most successful open source
release process around.