@geo_c,
The intermittent non-responsive JWM desktop you describe is one I have observed many times with JWM 2.4.0 as implemented in the original FossaPup64 9.5 and several releases of EasyOs. The 'desktop freeze' is not specific to JWMdesk but likely is due to the flawed timeout of JWM dynamic menus and associated piping issues originally introduced in JWM 2.4.0. I have tested and observed the same 'freeze' with JWM 2.4.0 installed in the ptheme/jwmconfig desktop environment.
Consequently, each time JWM is restarted (which JWMdesk does quite often) the dynamic menus (such as the Places menu) are terminated and dynamically generated once again. Unfortunately, JWM 2.4.0 does not handle this very well and the desktop may become (intermittently) unresponsive. However, thanks to bug reports by dimkr and 01micko at jwm github, this issue was addressed and hopefully fixed in JWM >= 2.4.2.