I continued my Turkish to include “Occupation”, which in this context means jobs, not occupying territory or being preoccupied with something. It was all vocabulary and no grammar, so it should not make it much harder to review older stuff. (When learning new grammar, Duolingo tends to use the new forms also in earlier lessons, except the very first such as common greeting phrases.)
After this, I have mostly done 20 XP a day in both Turkish and French, which is really only basic maintenance. I actually felt myself slipping a little on Turkish after a couple days this way. I think I need at least 50 XP a day just to water the field I have already sown. But I have faith that eventually the basics will be so obvious to me that I can expand without much need to look back, much as in French. There is short-term memory, there is long-term memory, but there is also what I call lifelong memory (although dementia might of course trash even that – but dementia tends to arrive years later in bilingual people.) Even though English is my third language, by now nothing short of massive brain damage could erase my basic English conversational skills. There is no reason this should be different with my sixth language if I integrate it into my life. Of course, that is a rather big if. Turkish is really just a whim for me, I don’t have any use for it. Or not that I know of. Sometimes we don’t see the use for what we learn until after we have learned it!
Anyway, currently on maintenance mostly. Not sure if my French streak is still unbroken, since Duolingo stopped reminding me of it, but Turkish is at 27 days and counting.