>> Just putting some feelers out. I've started work on a Captive Prince longfic (no estimate so far for word or chapter count),<<

Go you!

>> and I've noticed that I kind of... need support to finish writing things that are longer than, like, 10k <<

Lots of people do.

I will also add, this is something you can level-grind. If you write a bunch of long things, after while it just stops feeling like such a big deal. I've done it.

>>So basically my question is: if I were to blog about my writing process for a longfic for a fandom that you don't know, would y'all still engage? Or want to hear about it?<<

If I see it and it snags my interest, I'll comment. I like reading about writing. But I read my friendslist erratically.