@Glen *******
It's a tricky question because we don't have a definitive answer and situations can change. Phnom Pehn for instance seems to be counting them all, but Vientiane should be counting only the ones issued by them. Generally, 2 or 3 from Vientiane in a passport is safe, 4th they may refuse. That's exactly why I wanted to know how many from Vientiane did the OP have in his previous passport.
To be safe, I only hit one location twice per passport.