Maybe my reading comprehension is just bad, but have you tried out your theory with drinking before entering an area?
If not what prevents you from doing it?
(You seem to have tried out a couple of other things, why stop there and post it here?)
Apart from that you might be right on most parts but you are definitely wrong about reloading since the generated items only look similar on reload but can have different properties. (a belt might have had a bonus to lucky charm and on reload will have a bonus on thieving instead)
Also something you might miss but it is more an assumption than a fact, is that lucky charm doesn't give you a lucky drop when the little sparkling effect and audio happens. but pretty much every time you open a non chest container and still get an uncommon or better item.
I base my assumption mostly on early game because I know what's in containers without lucky charm or which ones are empty without it and a lucky charm of at least 2 will give you item drops in those (which are more rare ofc if your lucky charm is higher) so I highly assume lucky charm procs much more often than you would think by the sparkling.
