I don't downshift excessively. When I need to really pick up the pace to abort traffic and hit the fast lane, I'll drop her down and rip it hard. But I don't make a general practice of using any gears when slowing or coasting to a stop.
This failure is an odd one. It seems to be in the selector shaft, and is slowly beginning to affect all gears. Part of me wonders if it's clutch related, like the clutch is dragging and not letting the input shaft speed synch. But it still crunches going into 3rd even without using the clutch......
I do, as a contingency, have an extra Stage 4 disc, and 2 extra slave throwouts on hand. I just hope the trans I'm installing doesn't already have some issues. There isn't any really way to confirm problems until you drive with it. But I spoke to the seller, and warned him of the common problems, and he promised me that he will honor his 6 month warranty.
Chances are it won't last 6 months, but as long as it isn't already damaged, I'm not gonna pursue him if I end up toasting it.