How do I play with only a handful of my packs installed?

angua22892  There is no officially supported way to accomplish this, since, as you've seen, the EA App will override any settings you choose and reinstall your missing packs.  However, if you'd like to try an unsupported workaround, I do have a suggestion.

First, you can delete the folder for any pack you don't want installed.  Make sure the EA App is closed and the EABackgroundService is NOT running in the Task Manager.  (It would be in the background processes list.)  Open [install location]\The Sims 4; this is the default location:

C:\Program Files\EA Games\The Sims 4

This folder will have a subfolder for each installed pack, and you can trash them as you like.  (The Delta folder also has one subfolder per pack, but this is patch data, not the packs themselves, and shouldn't be deleted.)  The folders are labeled by pack type and release order.  Here's a complete list:

https://sims4.crinrict.com/eng/extras-2/available-packs-dlc/

Simply deleting these folders is only a temporary workaround, but it's possible the EA App won't reinstall the packs until the next time you update or repair.

If you want or need a more permanent intervention, create a text file with the name of a pack you don't want reinstalled.  Strip the .txt extension off of it, so it's simply labeled EP05 or whatever you choose.  The App won't be able to create a folder with exactly that name in exactly that location, and it won't be able to deposit files inside a text file (as opposed to a folder), so it won't reinstall the pack.  You might see a download error in the App, but you should be able to ignore it.