Great work getting started here. A few notes though. Firstly, I actually started working on this recently as I started in the last community call. Please publicize what you are working so we don’t waste time having two projects working to solve the same issue. If you’d like, we can coordinate work and do this together.
Second, I do not think that this is the correct method for going about solving this issue. While the UX of it is that we would say 50/50 or 70/30, we definitely should not be storing ratios and then calculating the amount every time. This actually would make it significantly more confusing for governance (more parameters to set) and add on unnecessary gas overhead.
What should be done is just setting the borrowRate and supplyRate for each asset. I started with this, but then got sidetracked on the whitelisting account project. You can see what I did so far here.