I've got the acorn, I've brought up Todd from the abyss, return to Oldfield, lo and behold he's got no new dialogue. Not about Todd or the acorn or anything. Ferryman's the only person I can give Todd to, and I haven't checked if anyone else can/wants to accept the acorn yet. Pretty annoying that I'm missing out on some XP and probably a few last footnotes of lore but I'm probably gonna continue on unless a fix is in the near future. Very anticlimactic way to finish off the DLC, maybe next run will be better.
I'll link my save files in case any of the devs want to sort through them. To be fair I did start my run when expedition dropped, got burnt out and only recently returned to it. I assume an update since then might've possibly broke my game, and that this is divine retribution from styg for abusing the jetski exploit.
https://mega.nz/#!NENBUCpR!F-WQEDSv0oDUFNs9yQ6MTzpAlOFjPtBe0YHFvi20NQkQuick edit, a thought popped into my mind. I'm gonna try and do crimson meadow later and see if Oldfield responds to anything I find there.
Another edit, one minor bug/oddity I noticed is when surfacing, it gives me the lines for descending in addition to the lines for surfacing, not sure if it's got anything to do with whatever flags oldfield checks to continue on but it's still kinda silly/immersion breaking for the final quest and another bug worth looking in to or fixing.