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Bad Lip intrusion only happens:
1) when the lips swell and the embouchure is not strong enough to keep them out of the cup
or more often:
2) more pressure behind the lips than the back pressure of the horn/mouthpiece, thus blowing the lips into the cup.

#1 happens when we do not pay our dues and practice too little
#2 happens when we take a classical music breathing approach with a large oral cavity, tongue low in the mouth and try to play a shallow piece.
Shallow mouthpieces require velocity not volume of air - and we get that with the tongue arched.

The lips can be supported solely by muscle strength, equilibrium of pressure in front of and behind the lips, or a combination of both. Shallow mouthpieces require more "equilibrium" and less lip mass in the piece! Bore that mouthpiece out and destroy the equilibrium!

Deep mouthpieces allow for intrusion to increase the sound producing lip mass in the cup.

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Whenever I feel blue, I start breathing again.