I just found out something quite pleasantly nice. My copy of Timbuktu 8.8.4 on my current main axe, the MacBook Pro, can directly connect with and control my 7100 running System 7.6 and equipped with TImbuktu 3.0, which I just acquired from eBay (the TB2 3.0, not the 7100).
I wasn't expecting to be able to do that; the compatibility matrix guide I snagged awhile back seemed to indicate that no version of TB2 later than 5.2.4 would be able to connect to something as old as version 3, which would mean daisy-chaining, with a version 5 of Timbuktu in between.
The real nice part here is that I'm setting up a System 6 machine, either an LC or a IIci, and of course I will want to remote into it. The entire reason for the purchase of Timbuktu 3 was to serve as a "bridge computer" between System 6 and Timbuktu 1.0.x (which I have, already) and my MacBook Pro. Having one machine in-between is going to be quite tolerable; I was worried about having to daisy-chain from MacBook Pro to a MacOS 8.6 box running TB 5.0 to the System 7 box running TB 3.0 to the System 6 box running TB 1.0... I may even luck out and find that I can connect to the 6 box DIRECTLY, since obviously their documentation on the limitations is just plain wrong.