i think the plugin menu had not yet existed before install ltplus. seems rb writer can choose location of script commands (per google help)
also system restore removed uninstall.exe, but i now think sketchup installer never creates an uninstall.exe (because su uses msi?)

to investigate further, i think i'll uninstall then reinstall su, observing file changes in app folde4rs
install some extra plugins. install ltplus. i expect the earlier plugins will still show after ltplus install.
IOW, i suspect that ltplus only "looks funny", but is likely OK.