No ReAction classes are opened during startup so their presence isn't going to affect the amount of RAM needed to boot the OS. The first time the AsyncWB or RAWBInfo windows are opened, several classes will be opened, which will of course cause a loss of memory until they are explicitly flushed by the user, or the OS needs to do so, the same with any other library.
I'm not getting any memory leaks here on a vanilla install. If you have a specific sequence of actions that result in a leak, I'm happy to investigate further and fix.