Paint, in any sane application, will not fill the weave. If you make it thick enough to fill the weave, it will run, sag and have problems drying and the weave will still eventually telegraph through. You need to have the weave filled before you start painting. The "Filling the Weave" Shop Tip explains it in gory detail.

The difference between filling the weave for paint and for varnish is what material you use. For varnish you need a hard, transparent stable base for the varnish. Unthickened epoxy is perfect. For paint, it doesn't have to be transparent so something like epoxy thickened with phenolic microballoons works well. In fact, because it's so much easier to sand than unthickened epoxy, it's actually practical to start with only the wet-out glass, slap on a really thick coat of epoxy/microballoons and after it fully cures combine all the weave filling, fairing and prep for paint in a single sanding session. I just did that on my WR18 a couple of weeks ago. I went from glass with the weave fully showing to ready to paint in a single 8-hour hand-sanding session. Microballoons under paint are really fast to work with.

In your case, you could switch and do a final epoxy/microballon coat but at this point it would be mostly to get practice for the next time you paint a boat. What I'd recommend is not putting on a full 4th coat of epoxy but instead simply painting the areas with the exposed weave. There's no point in laying down another layer of epoxy on a smooth surface just to sand it off again.

Good luck,

Laszlo