Since no one can explicity answer my questions, i just add some links here, that might help others that come here. The following posts were of no help. At least for me that wants to know things more specific.https://www.tek.com/en/blog/sample-processing-digital-oscilloscopeOriginal post:2N3055 demanded that i post this in the bug topic, but i believe there will be a lot of people who would not like that either, so i make a new topic:
Yes, i know, that not every edge can be triggered on, and the rate at which it happens will vary depending on a few things. But the behaviour i observed still seems quite strange to me. (Yes i am again advancing into the world of low sample rates

)
Said in a nutshell, it should be slower with more data to process, and vise versa. But it is not!
Its a 90 Hz signal.
https://youtube.com/shorts/XvDNO43fBtkDiscovered seemingly the same issue with seg aqcuire mode:
https://youtu.be/J5-ZZc376wQTrying to capture every edge for a certain amount of time seems to be quite a task to manage.
Edit:Made another Measurement:
- timebase 10us
- signal 90Hz square
- 200kSa/s
- segment mode
- trigger: edge rising / no holdoff / trace is filling the screen, trigger level OK
- Vector mode
- no measure or search activated
First test 3 channels on:
For 1000 segments it takes about 11s (measured with stopwatch)
Trigger output triggers about every 10-11ms
Second test only one channel on:
For 1000 segments it takes about 22s (measured with stopwatch)
Trigger output triggers about every 22ms