BPH, even when actually benign, does at least somewhat interrupt your sleep. That's normal, and does not mean it's cancer (so long as your PSAs continue to be low)

Alpha blockers, even though they help with flow, don't seem to help with waking up at night.

I have the issue as well, but I'm waking up between sleep cycles (every 3 hours or so) so I'm not sure it's impacting my quality of sleep (I'm more concerned with non-REM, as that's when the glial network 'power washes' the day's built-up bunk from my brain.) Waking up between cycles is quite different from having an alarm go off every hour.

If it gets worse, I'm considering an alternative to surgery called Rezum, which looks to be a relatively non-invasive out-patient therapy, with less chance of complications. Anything that involves a catheter is at least somewhat invasive, but give it a look, get your physician to refer you to a urologist and talk it over with them.

Agreed that high PSAs should not be ignored.