The installers I know are meticulous about penetrations on residential roofs. Typically the penetration is made, adhesive sealant put down, flashing, the penetration is filled with adhesive sealant, the lag screw is inserted through the footing, flashing, etc. and tightened into the rafter through the decking, then covered in adhesive sealant.
I have more concerns about removing the footings than leaks.
In theory that is how it is supposed to be done. In real life they will leak. Anything that relies on field installation is suspect of quality control and roofers are one of the poorest in that area. Just look at who is installing asphalt shingles! Hardly any of them speak English, nevermind reading English instructions or Spanish for that matter. If the 'solar guys" install the standoffs, what kind of roofing experience do they have? Caulks have a stated life, but hardly any of them will last that long under field conditions - dirt, contamination, temperature and moisture problems during installation. Then there is the cheapest bid syndrome. If the guy is lump sum he will use the cheapest labor and material, they not exactly looking for return customers. If the guy is performing the work as the low bidder, he not only will use the above but perform shortcuts that will result in poor life expectancy. I mean do you hear roofers and quality control mentioned, EVER, in the same sentence?
Yeah, keep Austin weird. (Reality is for others.....)
No personal offense to you Julie, seriously. Been there done that, drank the Kool-Aid.