Tret Cream vs Tret Gel + Water-Based Serums

For maximum Tretinoin effeicay, I like to apply Tret directly to my cleansed and dried skin (vs the sandwich method, etc). However, I was told by a friend that my Tretinoin Cream is likely creating an occlusive barrier that reduces the efficacy of my water-based serums that I apply after applying Tret Cream and waiting 5 or even 20 min for absorption and drying.

Is this true? My friend suggested I apply the water-based serums before my tret cream, which might only slightly reduce my tretinoin efficacy (vs a larger reduction of my water-based serums efficacy applied after tret cream). Or, she said I should ask my derm to switch me from tret cream to a tret gel.

Has anyone had this experience? I'm considering asking my derm to switch me to a tret gel prescription to maximize tret AND water-based serum efficacy.