I run synthetic even in lawnmower as I don't want to keep too many oils in my garage.
All my vehicles of last 15+ years run on synthetic, with only exception being Detroit that calls for low-ash oil and only last wife car was factory filled with synthetic.
I always observe lower oil consumption after switching, although buying used vehicles with several leaks it take me some time to fix them all and the observation might not be consistent.
Just a month ago I switched to synthetic motor oil and synthetic ATF on my 2007 Superduty.
The engine had some sweating under, but after the service I noted regural drips that would leave 3" dots on the driveway.
Spend some time under the truck washing and chatting on Ford forum to narrow the leak to main seal. Could not figure out ATF or motor oil as leak was too small to notice level drop.
Drove like that for couple of weeks and ... the leak stop.
Not even sweating I had for last few years.
I am skeptic about engine self-healing, but for now I am happy camper.
Hope you will be too.