M3 Tap Characterization

I was having some trouble tapping M3 threads directly into my prints, it kept breaking apart at the layers. this operation worked with a couple other filaments, so I created a couple test pieces to see what the problem was.

The Tap test has holes at 2.5mm, 2.75mm, 3mm, and 3.25mm to determine the optimal size (drill size for M3 thread is 2.5mm) the holes are placed at right angles

The Heat tower is all holes at 2.5mm and can be printed at different temperatures to see if anything will break.

spoiler alert:
for my printer I found that 2.75mm holes could be tapped without breaking the print in the XZ plane, but 2.5mm holes were fine in the XY plane when printed at 200C. I also found that I could tap a 2.5mm hole in the XZ plane without breaking at 205C