Normally Visit pass products are setup to be sold with set of themes/languages permanently, however after several months some themes/languages are not available anymore and they don't want to provide these unavailable options on sales.
Removing themes/languages from future timeslots can already be done at Visit space setup but due to complex steps required, a simpler and quicker way is necessary.
Modify future themes/languages directly from Visit Pass product parametrization
The improvement is simply re-using MODIFY themes/languages option (Visit space - Timeslot) on Visit Pass parametrization screen (Timeslots menu)