Hey there! faderift might be a good fit for you. It's a small game based on the Dragon Age game series (but being canon familiar definitely isn't required—it's an older game that's spiralled pretty far and away from canon events now). From your checklist:

— slow to moderate pace, backtag friendly, easy ac ✅ We're all old have have RL responsibilities that keeps the playerbase pretty backtag friendly; the ac is simple and designed not to punish folks who are backtagging threads.
— not really interested in sex games ✅
— 50/50 on memory loss ✅ No memory loss
— down for basically anything else ✅ FR is a fantasy game focused on a war against NPC big bads. I'd currently describe it as action/adventure/sol-in-an-interesting-setting type games. If you want to pursue the war plot, there's a lot to interact with (or create), but if that's not your bag then you can SOL it up with the rest as window dressing.
— slight preference for jamjar over au ✅ Canon characters can either be jamjarred in via a magic portal called a Rift, or be AUd.
— dreamwidth only ✅

Other misc notes:
★ Baldur's Gate enthusiasts; I think 90% of the playerbase is chewing through the game right now 🤡
★ We previously had a terrific Astarion in game, and I bet you could get a jumpstart on some neat CR if you cared to
★ Player Characters skew older; I know this isn't a big deal for everyone, but worth noting we have a good number of characters in their 30s-50s
★ Ye olde tdm