I havent tested it yet, but theres a trick/workaround ive used in the past- that as far as i know work with any apps: making a junction link.
junction links are sort of special ‘shortcut-like’ for folders that, for any or most apps, is seen as an actual folder. That way the app would read the folder its expecting, find a junction and read its contents normally… meanwhile the junction would be pointing to another location, like a different hard drive.
The easiest way to make junctions on windows (without command prompts) is Link Shell Extension, a free app that can be used to make junctions, hard links and a few more tricks.
if youre on windows:
1- install link shell extension
2- with anytype closed, MOVE/change the folder’s location somewhere else
(better to copy, then rename the folder- just in case it doesnt work so its easier to rename the folder back later)
3- in the new place you moved the folder to, right click on it and choose ‘pick link source’ (its a new option to right clicking that link shell extension adds to windows explorer)
4- go back to where anytypes folder was meant to be(its original place), right click anywhere on the folder (its white area) and choose ‘paste link as’ -> ‘junction’
And thats it. A folder with the same name will appear, probably with an overlay arrow icon.
Now launch anytype and see if that works- if it will open normally… then check on the folder, to see if it created a new data folder or not. If not its working- reading the junction despite the files being in another drive.
Of course when using junctions DONT change the folders location- that would be like moving/deleting the folder, and will break the junction link.
I only know how to do it on windows, but junctions can also be created on linux (and i presume on mac, since its unix based)