So much learned here!

Now I get what PRx is for. Sort of feel a little Doh over that. I prolly would have gone years without seeing it. And its so much more intuitive. (number of cycles - 1) THANK YOU!

I love the toggle replacement

Not only did you answer my original question, but you also did the work for me. To be sure, I will not be going crazy in the ISR, in fact the only thing it needs to do is PORTC = PORTA. the rest is for debugging and will not be in the final program. I may keep a counter in there for something.
Is it safe to assume DT_INT cost about 20 cycles when not used with PBP handler? This is just good to know.

I must admit, I'm not sure I get the rules for using LATx, but easy enough to just not use it at all. I suppose you are saying LATx=something is fine, but not much else.

I think I am most excited about the PRx knowledge.