Good plan Tanya,
I personally keep things simple and always use a take profit and stop loss. I just use a fixed stop loss also.
For M15 I think a good range is 20-120, but I would increase the upper range a bit for higher timeframes (say 150 for H1 and 200 for H4).
If you are getting plenty strategies coming through using those ranges over approximately 5 years of data then all good :-)
If I run my reactor and get about 50 EAs overnight on a pair and timeframe then I am pretty happy. If a pair has too much more than this then I’ll make a note that can change the settings a bit for that pair and if too few then likewise I will need to relax the settings.