I've only arrived at the LCC end once, and I didn't have an immediate connection (my onward flight was the next morning)... but I don't recall there being an airside route from the LCC end to the "main" Schengen gates, so it's likely to be a case of going out through security and coming back in again.

At 50 minutes I'd say "no chance"

In fact I would never EVER take that kind of connection on separate tickets, unless the onward flight is on a flexible fare.