Actually, yes. The end of last year either LAS to PHX or the return. Heavily delayed inbound flight and short turnaround time. The GA said he wanted to board back to front by row number, all through the front door. Said it would be quicker.

If I recall it was something like boarding by the last 5 rows (and first class); then the next 5 rows and so on. Worked fine, no idea if it was quicker though.