I’ve been using Lingq for about a week now, so I’m still a new user and learning all these features myself. Initially, I was tagging each word as I came across them, but it became too tedious. After a couple of days of that, I reset the whole language to start over. I then imported about 20,000 Japanese words using the .csv file method with multiple appropriate tags for each word. What I found is if you reimport the same word, it will amend the additional tags. I’m using tags to indicate the JLPT level, whether the word is Katakana, and which textbook (Genki, Quartet, Tobira) along with the chapter number the vocabulary word appears in. Apparently, the tag names allow for spaces. I almost gave up on the .csv file method, until I realized I had meanings with commas in them. After I got rid of the commas, it was a quick and simple process. So yes, the .csv file method does work and is flexible enough for you to set up your vocabulary, meanings, and tags however you want to set it up. I used Google Sheets to create the .csv files. I sourced the various terms and meanings from shared Anki decks that I extracted into Google Sheets.
Maybe someday I’ll take the time to learn about .csv files. … Glad to hear it worked out for you. Personally I’ve got my hands full with the three languages I’m trying to learn, no bandwidth to learn stuff on the tech side.