I've had multiple companies expect me to take 8+ hours of PTO for a job interview. I ended up taking an entire week to fit in all the interviews and I could easily see myself having filled in the down time in that week with ~20 hours of work while I sat on planes/airports and such.

I'm not seeing this as much different and I get paid twice for the twice. I doubt they want more than 40 hours of work out of you in one month while you work full time on a separate job.