ive always used the oldschool way i guess?

i have 2 sets of analogue gauges, 1 r-22 and 1 set for POE oil systems( 410, 404a etc 134a etc)


im lookin into these new fancy digital gauges because a few people on here recommends them highly.


my question is, if im spending 4-500$ on a set of gauges, do you only use them one system?


or do you hook up your nitrogen and flush each line/manifold out each time?

seems very tedious but i guess its the only way?
thanks in advance for the input.