That's the plan, but in my view, TotalFinder & TotalSpace already do work with El Capitan.
At the moment, I think there's both a message issue (the interpretation of supported) and a perception issue (how that message was interpreted by users).
Let's look back prior to me taking over these apps. The message I was perceiving from BinaryAge regarding TF/TS on OS X 10.11 was that they could never claim 10.11 was fully supported.
I'll explain what that means to me by way of example. SizeUp, another app I develop, currently states that OS X 10.6 is the minimum requirement, when it's actually possible to run on OS X 10.5. I just say 10.5 is not supported because I don't want to maintain a Mac running OS X 10.5 just for testing =P
So in developer parlance, saying that something is not supported or not fully supported doesn't mean it won't work, we just can't guarantee it will work in the future. It's a hedge against Apple pulling the rug out from under us and making apps like TF/TS 100% impossible to run. When the reality is, Apple just made it more difficult for users to install and run apps like TF/TS in OS X 10.11.
However, it seems the message customers perceived was that TotalFinder and TotalSpaces don't work on OS X 10.11 and they're not being developed further. That couldn't be further from the truth. I'm trying to change this perception and reverse the momentum it has.
What do people think? Perhaps my view does not accurately reflect the situation.
I would like to hear more about this idea. Perhaps a graphical mockup would help. Maybe start a new topic?