We have no idea what the substrate is, if there even is one. With regard to the bytecoin development community, so far I've seen one fix from monero get pulled back to bytecoin, and little if anything going in the other direction. If there are stores, exchanges, etc. for bytecoin, then let's hear about that. Failing that, there is no substrate. It is all a mirage.

But like you I am mining both and taking a wait and see attitude. I think monero has just a whole lot more legitimacy and transparency at this point, and that counts for a lot. Just the fake cicada 3301 references are enough to convince me there is an element of scam to bytecoin, but those could possibly done by someone with no real connection, so we can't be sure. It smells bad though.