yeah, I'm with you on this. I've tried various types of pet-g and generally found that pla is stronger.
Even some small clips that need to be flexible - came out better with pla.

Printed some fairly large brackets recently, that needed to have good impact resistance and a little flexibility.
Was showing them to someone in my workshop and said, these will flex. And they didn't, just broke really easily.
Ended up making the final ones from flexible pla - which is genuinely indestructible and rigid enough for what I needed.

One of our members who works in injection moulding said that pet-g is actually stronger if you print it at a lower temperature. Think I've gone down as low as 225. but the parts just fell to bits.

For a stepper motor mount - you actually want it to be rigid - so pla would be your best bet anyway.

I do wonder if pet-g, while easy to print without an enclosed print volume - might actually need one to get to full strength.