I spent the morning sanding Thursday's application of filler, then sprayed it with another guide coat of primer and sanded that off too. The result was pretty good – the light grey areas shown in this photo are actually historic low spots that are now filled and sanded level. The dark grey spots are the only remaining low areas still needing filler. Most of these are in the area of the slider seal "doghouse" which I have yet to do much with.
Since I am running low on micro, I mixed up a batch of Superfil from a quart kit that I'd bought a while back. I've never used this stuff, but people seem to rave about it. Each of the two components is the consistency of peanut butter, and you mix them 2:1 by weight or volume. I eyeballed three plastic spoonfulls of blue goo to one and a half of tan goo.
Since I had a little extra mixed up, I started applying filler to some of the more egregious areas on the underside of the canopy skirt. I don't intend to go for a perfect finish on the bottom, since it will be hard to see from inside, but I do want to at least fill in the voids.