When you bring the witness back online about how long does it take to sync up? (just gathering intel and weighing some options.)
A full replay at this point probably takes somewhere between 3-5 hours (provided you're doing it all in RAM), which is just downloading a snapshot of the chain, then replaying it to rebuild the shared memory files.
You do have plenty of room for expansion though, now you can lease a couple of U's to some of the other witnesses, or drop some of your EOS gear in there as well.
The one concern about getting other witnesses is that it would end up centralizing things to some degree, but you're right, I could probably host a few backup nodes for other witnesses in case of emergency. I do plan on dropping some other block production resources on the other server (EOS as one, probably Decent/Muse/etc in the future).
I'm relatively new but from my perspective, you have a business to run.
A very good point - the hard part is that being a witness is a completely unknown business model, with currently EOS leading the pack on that grand experiment. It is a business that has to be run, so hedging bets is a great move, but without an actual product/customers the business is completely depending on the DPoS votes and the political process.
The conversations we've been having while building Greymass have been incredibly interesting in this regard. As an organization, we're completely reliant upon the stakeholders, which almost makes it more like a political party/organization. However it's run more like a software company on the inside in order to run the infrastructure and create the products that the community is in need of.
What an exciting time to be involved in this space. It's uncharted territory and we're all a part of it, figuring out how best to move through the space.