Many thanks, @Sandy_DLR, for this really helpful advisory. Still, found some glitches in it:
1st:
This must read instead:
tx push -s --keep-translations
since translations must be kept when source is updated, not when translations themselves are updated; it is without function in -t mode.
(confirmed by consultation with the transifex help desk.)
2nd:
Your source file upload screenshot shows a checkbox “keep existing translations”, which doesn’t exist, even in resources which have a key-value paring, like .strings files. So this method won’t work.
3rd:
The Using the Client advisory states under the header “Pushing files to Transifex”, subheader “Other Flags”, that you can set this on resource level in a config file:
--keep-translations: If present, translations of source strings with the same key whose content changes will not be discarded. This can also be set on a per-resource level in the configuration file.
While it doesn’t mention, how to do that. So my question is: How to do that?