sorry that I did not react for quite a while: my rehearsals are just very time-consuming and challenging.
thank you all for your answeres - that's very helpfull!
@Woland
as always from your side that's a very profund answere. thank you very much, especially for all your practical suggestions how to deal with my problem.
@Mr_J
also this is helpfull as a direction for me.
@Josafat
this is a very interesting observation - thank you for sharing it.
so far I am still working in 3.0.7 but I should come to a decision in this week and I have the tendency to follow the first suggestion of Woland (even if the internal hardrive of the old macpro is only 500 gb) and try the bootable partition with a newer os. as I jumpt from high sierra with a new M1Max-macbookpro directly to monterey - which works ok for me apart from the incredibly annoying orange dot - I'd be be very curious to know if you have a clear recommendation for mojave, catalina or big sur?