If we are picking buttholes, 1.8B was very nearly 1.9 if not for community backlash against the idea
But yeah letter versions are typically bugfix's with the odd small content drop in-between.
1.9 is taking longer than normal cause of the sheer amount of work it will take to make good and bad endings for every main character, then continuation of Alice's quest and the updated love route for Anna to make it on level with slut etc. Communication has been handled badly, there is no shying away from that, but hopefully lesson learned. Personally I would prefer to wait a little long so we do not end up in another broken/revamp save state again and a load of glitched quests.
As for Roundscape Eclipse, years have been burnt into it at this stage so I do not foresee a derailing in preference to Starmaker. But heck knows at this stage what comes after 2.0 and the break. There are sure to be thousands pushing for more Starmaker, but with these being Kal's personal projects he might choose to go down the path of a Arenus Remake or something completely different..
Roundscape Adorevia 6.9 Release, I think we have more chance of Half Life 3 at this point. If there is a definitive answer to this long held question, it might be a good idea for one of Arvus Games to post it on the Steam forums.
Not to mention, Kal normally likes to do a game jam around this time of year as well, so that might cause further delays if he is partaking.
Long story shot a little more community management would go a long way, and hopefully stop a lot of the Negative Nancies... though there is no pleasing some people so you can never win 😔