This is regarding Windows on PC, but I assume it's not available on Mac or anything either.
I used Chrome previously, which had the great option to add specific taskbar icons for whatever profile you liked. This meant I could have a dedicated icon to click for my school profile, which saved time and was convenient. Even if I didn't have the browser open at all, I could visually see the profile badge and knew what I was clicking on. Please add this option to Firefox! The profiles work great, they just need an easier way to differentiate them between on the taskbar! I have the profile-specific desktop shortcuts saved, but I tend to use the taskbar.