I'm not sure, I never heard of Solaar until you mentioned it!
I find Piper to be excellent though. For my G600 I can control the LEDs, remap the buttons, set the various DPI resolutions and control the report rate. It does everything I used the old Logitech Gaming Software for (fuck Logitech G Hub).
Yep, Piper is what I use with my Logitech G600.
Social media, search engines, email, banking, shopping, news etc. I even have one for my self-hosted stuff.
The only real limitation I've had so far is that it doesn't have enough colours. I think there may be improvements on the way though as Mozilla did a survey about it a while ago which I completed.
You may want to keep some things in the same group such as Reddit and Youtube. Without cookies to keep you signed in on Youtube, embedded videos on Reddit often won't work.
Seeing as people get away with this shit all the time, this is what Multi-Account Containers on Firefox are for.
You can containerise each website or list of websites to a different tab group that can't share cookies with each other.
Yeah, I think so. I had a backup G600 that replaced my old one a couple of years ago.
I think they discontinued it before then brought it back for a while but looking on Amazon UK it seems unavailable. RIP G600 :(