Yes. You can safely work on any component in AMOS. If it is put to the "standard components" whitelist or not does not have any consequence on translation data or their distribution. The translation is not lost. The only two things it affects are:
- Standard components are displayed as such in the Translator filter form field
- Their strings are counted into the translation stats at download.moodle.org pages
All your translations, be it for standard modules or not, are included in generated ZIP files. So sites have them available even if they do not have those add-ons installed. It was designed this way so that when a contributed add-on is installed, it is immediately available in the localised version (if such translation exists).
So shortly, yes. You can translate any component in AMOS even before it is whitelisted.