Change language in Sims 4 without reinstalling

I have been searching for a way to add a language to my current install of sims 4 with the purpose of being able to switch back and forth easily (editing regex is easy enough for this purpose, as I don't have to sit through installations of all the packs each time).

I stream the game in english but I also have a swedish youtube channel I want to record for, with the game in swedish.

I was happy and thought I had found the answer in another thread, but while locale changed, the language strings for the other language was missing. When I added a question of how to resolve it, the thread was closed because the thread was old, without further direction to a newer thread.

Does anyone know how this can be achieved?

Uninstalling  and reinstalling the game with all the packs twice a week (at least) is not something I want to do. It takes too long and sometimes the game duplicates itself in such a way that my 100 gigabytes of free space is not enough and I get stuck without being able to play for a while.