Not only multiMAN clears the remaps. Also IRISMAN and the other forks.
Both backup managers used to compete for the control of the system.
Therefore they cleared whatever the other backup manager did in memory.
webMAN MOD is permanently running, so there is no need to clean the remaps that it created and manage
Your hypothesis could be true. However I think the issue could be related to the dynamic memory allocation (heap memory) used in
mappath.c of PS3HEN.
Mamba and Cobra 8.4 preallocate the
map_table in the stack memory. This ensures that the mapping always will be successful. While the malloc may fail and the exception requires to be managed.
https://github.com/Evilnat/Cobra-PS3/blob/master/8.4/4.90/EVILNAT/PEX/SRC/stage2/mappath.c#L31
Additionally, map_path is more use today than its original purpose:
It was originally intended to remap GAMES folder and maybe 2 or 3 other paths.
Nowadays the payloads, webMAN and modders use many remaps, which could make the original dynamic malloc infective.