I like the approach but it might be worth it to create a trans_LANGUAGE column. Committing to multiple languages on a site isn’t a small task and this would separate each translation out into it’s own column.
You’d get a couple of benefits from that approach.
First, with updates. Variable sized columns that can store blobs have to worry about space reallocation on updates which can stress the database a good bit as it grows, especially with any significant update frequency. By having a column-per-language you’ll end up with multiple smaller fields that update less frequently on their own.
Second, if you know the translation that you want to get back, you can request it in the select rather than the entire JSONB for every language. If there are multiple fields for the variation, you’ll be able to easily query the whole set of translations on that row for that language with one field, rather than having to separate it out of the JSONB. It will also speed up parsing the JSONB by keeping the size consistent.
