Add to this catalog uses a hidden import dialog. So if you have the option to create 1:1 preview on regular imports that is what it is doing.
Do an import and select Standard preview and that will set it for add to catalog.
Thanks for the reply! Unfortunately, I forgot to mention to mention that I have tried exactly this approach without any luck. Just to be sure, I tested it now on the latest LR 2015.10 (Win10) with import and previews set to minimal. Then after running export with Add to Catalog, the LR still builds 1:1 previews.
Did you actually do an import with it set to minimal? For that setting to stick you have to do an import.
Also try restarting LR.
Yes, I did a real import of a single photo. Now if I open the Import dialog, the "Minimal" setting is there as a default.
Good tip about the restart, I have not thought about that. But after restart the behaviour is the same.