Thanks Bzb. I’ll try that.
Right now what I do is to download the map from cloudmate as layer 1 and use my map (which is already very extensive) as layer 2.
This way I can always disable one of them, depending on the use.

Usually I agree but in this case I feel that there is an overload of information and a point in the right direction could save a lot of time.
My first question is probably - Which editor should I start with? (Josm, Potlach, something else?)