Filling deep voids with clear epoxy resin

I have a few questions about using some epoxy resin for filling deep cracks & knots that normally I fill with coloured wood putty.


1 - Does the clarity yellow over time indoors with just typical house lighting?

2- Should a sealer coat of finish be used first so the wood doesn't absorb alot of the epoxy?

3- I plan on staining, but not sure when to do it? If done first I think I will accidentally rub through the stain while brushing over the filled up knots. But if I stain later the stain might colour the clear epoxy.

thanks