A couple more things:
The battle prediction not populating thing does not appear to be a time or processing issue. It just doesn't appear sometimes no matter how long you wait. Usually, but not always, looking at a different battle calculation, then coming back, fixes it. FWIW, I've never seen the calculation take even a second to appear. If it's not instantaneous, no amount of time (that I've waited for, which is a few minutes) will bring it up.
The battle viewer is misreporting damage in the summary at the end. The combat log and my ending ship hit points will agree with each other, but the summary will say something else. Like I may take 5 points of damage in the fight, and the summary will say I took 3. It seems to always under-report the damage.
Ships are still showing damaged when they're not, and also vastly more damaged than they actually are. As in their health bar might show them to be barely alive when really they've lost only 10% of their HP or something.
Unrelated but I really wanted to mention this somewhere: the Union Center building you get with the Egalitarian ideology says it adds +5 manufacturing but in 1.6 it added +5 manufacturing and +5 shipyard production. Now in 1.61, it ONLY adds +5 shipyard production with no general manufacturing bonus. Just FYI.
There are lots of great fixes in 1.61 though, and I'm really liking it!