Try
1)Tools > Options > Library & Folders > Manage Library fields > Add New Field.
Name it "HIDE", Flags choose all, Data type, "List",Relational,"Not Relational",Edit type,"Standard", Check "save in file tags", OK out.
2) r click main audio > Customize view > set rules for display > New rule box 1 "HIDE" box 2 "is not any" box 3 "YES" (leave "empty" unchecked) , Apply, OK out (Overide warning and "Overwrite", but can
always be undone)
Done, took 5 mins.
Now select all tracks to hide and in action window tag with hide.Job done.
Optionally can create a customized library view under Audio that only shows [HIDE] tracks so you can see them and un-hide them.Remember to uncheck "inherit rules from parent" for this view (otherwise will inherit the 'hide" rule.
It would be elegant if MC had a hide/unhide option, and the clever coders here may be able to configure it also? However this is a 5 min workaround to consider in meantime.HTH