Hey Matthew, you are welcome re my suggestions. Glad they helped :-)
Requiring 300 trades over 2 years data will definitely be much easier to pass for M15 than H1 so that makes sense. If you want to get strategies for H1 also then I would be increasing the number of bars used in backtesting to be closer to what worked well on M15.
Not sure re NZDUSD, maybe try initially relaxing the acceptance criteria to get 100 or so eas into the collection and then investigate in the collection what seems to be the criteria that it is struggling the most to pass and make a decision about how best to proceed from there.
Well done on the great results so far. Good to see :-)