Thanks Mike. I think people got away form the original question and started giving personal preference. Which although i do appreciate it, it can cause some confusion.
This statement of yours answers the OP perfectly.
"body shop industry working on fresh paint did not want to seal the paint and hinder out-gassing "
I also understand that they have fillers that could prove helpful.Perhaps I'll grab a sample on my order and see if it helps on my Black car.
It sounds like you have a good idea of their use. I used glazes to help fill light swirls so they are not as appparent between polishings as I did everything by hand, up until about a year ago. I appreciate Mike's comments about also reducing the amount of paint you remove from a car to keep the swirls at bay.
For me, I also thought they added gloss above and beyond anything in the wax or sealant that you are using. Maybe it was just marketing hype, but I bought into the concept that glazes also helped feed older and sun dried paint with oils. Some colors seem to benefit more than others with reds and blacks becoming More Happy. Some sealants apparently don't like certain glazes, so check with the sealant manufacturer.
I used to use megs #7 before applying waxes going back into the 70's. Around 2000, I started using OG Omega Glaze before their Blitz wax and it minimized the perception of light swirls for many weeks between waxing. I would guess that there is synergy between glazes and certan waxes as well. We live in SoCal, so there is not much rain but I did wash 1x per week plus used a QD several times per week.
Omega Glaze helped clean the paint a bit and hid stuff when I didn't have time to do the whole monty. It's not a panacea but it can help when you want your ride to look good but don't have the time to make it perfect. Both of these glazes amped up the shine and gloss before applying a wax. I have never tried Omega Glaze or #7 under a sealant or even a hybrid wax like Fuzion.
I currently have CG's new Glosswerkz glaze under WG DGPS on my wife's BMW after polishing out the swirls. It is a polymer glaze that is supposed to be safe under waxes and many sealants, and seems to work without issue. The bimmers paint was just polished (Megs UC then Opt Hyper Spray Polish), however the gloss was enhanced vs the polished-only paint.
That being said, I don't see a huge difference in gloss between the hood with the glaze vs. the rest of the car with just the sealant. There might be a little more wetness or effect to the finish but I already like DGPS. Water beading is evident on all surfaces and the paint remains slick and smooth, so it doesn't look like the glaze has run off the paint after the heavy rains we've had for the past month.
The bimmer is a champagne beige metallic and the paint is in good shape anyway. You're probably more likely to see your Black Porshe's paint pop more than our lighter colored car with a glaze, just as black seems to benefit from that extra gloss and wetness.
Can't wait to hear how it works for you and see the before and after pics. Take care!