Thousands separator with apostrophe

Dear GD team,

I am setting up a real-estate directory and was trying to use the predefined field “Price” which is basically very good, but lacks one little detail for proper formatting of the numbers: the thousands separator option is missing the format with an apostrophe (e.g. CHF “1’234’567.00”), which is standard in Switzerland.

I managed to add it in the file “custom_fields_functions.php” as an additional option (see attachment), and it seems to work, but will unfortunately get lost in the next update.

Would it be possible to add this format in a next update?
Or as an alternative, can you tell me if there is any hook/action I could use to obtain the correct layout for prices?

An additional question: is it possible to have a multi-currency setup for the price field? There will also be properties sold outside of Switzerland, which will be handled for example in EUR instead of CHF, therefore I would need to distinguish these cases.

Thank you very much in advance for your help.

Kind regards,
Aron