basic electronics question

I'm better at electrical subjects than electronic but it looks to me like Q5 and Q6 are the traditional MOSFET complementary pair. Looking at the note at the top, the only reason for R53 is to get a reading for the idle source current for Q6. Looking at the rating sheets for the IRFP140, its maximum Source-Drain voltage is 100 VDC so I'm guessing the 40 VDC isn't a problem. If it were me I'd fire it up and adjust AP1 as per the note and call it good. But again, I'm better at electrical than electronic topics.