correction, my run up is approximately 1-2 minutes, not 5-7. 5-7 minutes is way too long for run-up, unless I have a triple cheeseburger in hand that I've got to finish.
5-7 minutes is total time from engine start, to taxi a looooong way to runup bay, and finish the run up.
I think I've gotten the answer I need.
1) Do it in a clear area in the apron (with situational awareness)
2) Right before takeoff (it's ok to hold for 1 minute on the runway to do the runup)
As for running up while taxiing, I'd prefer not to do it now, as I have quite a few items on my checklist at the moment, and I prefer not to miss out any crucial items.
I got it right?
So far, I'm in my hour building phase towards CPL, and therefore I'm doing quite a bit of flying into airfields octa, staying a night here and there, and flying out the next day. Hence, it's one of my first few trips where the first flight is octa, hence the need for runups.