they are sold as - rated for 34A as the links you posted also - i have yet to find any that are rated for more than that - but yet the original PL 8 plugs - never had an issue that i realized at least
Ratings like that are at best a guess.
A clean well fitting set that have good design may work at 30 to 50A without getting hot. All depends on fit, cleanliness, wire capability, and actual plug design. Its impossible to say 34A exactly. There is no sudden point where they will give problems. If they are cool/warm at 40A then no problem. If they are hot enough to melt, then thats either a badly designed connector or its dirty and making a higher resistance connecton.
The ones that are used by the charger manufacturer are rated at 32A. And tested to 50A by me many times. They get warm, and are fine. Some cheaper or worse designs melt at 20A... So only use the ones like the manufacturer sold. And an occasional squirt of switchcleaner to ensure they dont go high resistance or loose from physical damage. The contact area on those is longer than most 4mm bannana connectors. And doing that I never had any problems with them. I am still tempted to fit a Anderson to each however on a short cable.