Slowly but surely, as they say.
Made my first attempt at putty filling. Mixed results there; binder arms are looking semi-decent after priming. Forearms on the other hand... I guess I should have added more putty there. Sanding down convex surfaces is rather hard. The end result isn't exactly anything to write home about, but I don't think I'll redo it — at this point, it's just too tedious. Putty is rather brittle once it dries up, but it's rather hard to clean it up completely from nooks and crannies where it has overflown. Plus you end up with tons of fine gray mist-like powder.
I've also realized that my assumption that SD model will be easier to work with might have been false. Sure, it has fewer pieces. At the same time, those pieces are more convoluted and complex. This makes both spraying and sanding a bit of a challenge; how do I get paint to all of those surfaces without overdoing it? On top of that, I've decided to test spraying at 40 psi. It makes the whole process faster, but at the cost of less control. Primer seem to flow much quicker, and I ended up with more pieces where it built up unnecessarily.
I'm still running with just 20 painting sticks. Turns out, it's hard to get ready made sticks like that outside of Japan. I got some crocodile clips from certain Marcan (thanks!) but I still haven't bought skewer sticks to turn those clips into anything useful. Need to resolve this sticksy crocodile bottleneck soon. At this point I have almost everything primed. That is, I still need to so some work on those chubby Kshatriya arms. They have an actual joint there, which makes them hard to prime. r/gunpla suggested a couple of solutions, out of which I've picked the laziest one — masking one of the parts. But that's still to come.
On the front of embarrassing news: got a remote for my camera, and spent only one evening perplexed by its lack of cooperation. Turns out that telling the camera to listen to incoming IR signals is a good first step. Perhaps I should have read that manual. Last but not least: started putting together Yonen Kirks' sniper Zaku I. I like snipers, and Kirks short but sweet performance in Unicorn gained him a spot on my shelf.
Coming soon: actual painting!