When using a larger number of templates, I consider it beneficial to have multiple sets of template settings which disable or enable a group of templates by a single mouse click especially if a hill shading image or aerial photo is split in multiple images:

The current state is a Proof of Concept:

• The code needs refactoring (encapsulation, naming of functions and variables, documentation)
• Tests need to be added
• It's currently focusing on the desktop version
• It's needs to be discussed whether changing between template selections sets shall be possible by a key (e.g., use F4 instead for Overprinting simulation) or by extending the wheel menu
• Icons different from those used for adding and removing templates itself

Nevertheless, it's fully working (although no guarantee of having no errors or even crashing Mapper):

• Templates selection sets can be saved to and loaded from a map
• Templates selection are stored such that the first set is stored as today, the remaining sets are stored in a separate structure which is silently ignored when loading from a Mapper version which does not yet support templates selection sets => maps are fully backward compatible.

See also #118, #534, #1185, #2242