I have to agree, saw the latest changelog and was thinking that's not a lot of progress for a RPGM game. Like I get that scenes might take a while to make art for, and quest dialogues have to be written... but other than that the actual coding of this stuff should be pretty easy to do in that engine. There's a reason everybody and their brother uses RPGM to make low-effort h-games.
This one seems like it has the potential to be a GREAT RPGM game (exception rather than the rule) but I hope this isn't a case of "we're funding this thing on subscribestar/patreon so we have no incentive to work quickly". Considering most complete japanese RPGM games are a whopping $5-10 on DLsite, that whole funding model seems like it gets abused to hell and back by devs.
EDIT***: I would temper that assessment with the fact that the devs are currently only pulling in a little over $700 a month on patreon for this + probably a similar amount for subscribestar (can't see actual number)... so they're not making "quit your day job" money on this. If its just two people who also have to make money other ways... yeah this could take a while for good reason.