That’s an old problem and i find it is always important to solve / improve it.
Without that, i don’t understand how the others deal with these multiple Dev Tools open…
If you can explain to me, i should be great.
The only trick i find around it, is here:
Bring inspector window to front when Firefox gets focus
One trick that can be helpful to know: if you press a DevTools toggle keyboard shortcut (eg F12) on a tab which is linked to a “separated” DevTools window, it will automatically bring the DevTools window to the front.