Alan
Not a thread-hijacking. Rather you contributed aspiration and inspiration.
I'm really impressed with your sub-7:00 500 yds. and especially that it happened, when you weren't overtly pursuing it.
Also great advice from Andy.
Galax, if you find your SPL increases by excessive increments, then adjust your tempo by smaller increments.
I just posted today's practice
here. I didn't use TT, only SPL and time today. My post is #11, top thread on p. 2.