I just installed Lineage OS on an old Galaxy Tab S6 Lite.
Turns out I need MicroG to make one app work (Clip studio Paint).
This is my second Lineage install, so while familiar, I am still new to it.
Do I have to re install the Lineage fork with Microg found here from scratch?
Or is there a way to get MicroG with the existing lineage installed?

Usually you just need to install microG services (and the microG companion if needed) from their F-Droid repo.

i have the microG fork on my S6 Lite and works without issues. if I remember correctly, I did a dirty flash over stock LOS, without wiping data, and all my stuff remained untouched.

one caveat, I haven't upgraded to 23 as I have doubts my old device with just 4 GB will be up to task, still on 22.x. so if you succeed, I'd appreciate a ping-back with your impressions on speed and such.

How would one go about doing this? I can't quite figure that out via the Git hub page.
(I'm still in the "needs detailed instructions" zone)

Edit: I figured it out, there's a bloody tutorial 😅

Edit2: for clarity, A tutorial to use the MicroG QR code to add repo using F-droid.

that's a tutorial for fdroid?

anyhow, you flash it the same way you flashed your stock LOS, only you don't do a wipe beforehand; that's called a "dirty" flash. make sure the McG-LOS is same or newer version than your stock LOS.

Yes, I was getting stumped at the QR code on the MicroG github downloads page, turns out you can just add that through F-droid.
that's why I needed the tutorial.
CSP is working now with Lineage 23 and I'm still testing it's abilities.

Learned how adding Repos to F-Droid works, so this was simple (once I sussed it out 😅 Ah being a beginner).
Thanks!

This whole system of custom repos does indeed need a bit of work to make it more intuitive imo. Some F-Droid clients like Droid-ify fortunately make this a bit easier by already providing some popular repos (including microG) that you just have to enable.

Glad you figured it out, though 😊