Everything should be sharable in my opinion.
I think that 24 hours as a max would be sufficient for every drop.
Then outwith those first 24 hours, it could be an exchange like PC/credits/DZ funds in exchange for a piece of gear/weapon etc but it would need to calculate cost based on GS and money put onto rolling or something like that.
I have noticed that there is a very big difference between GS268 gear you get in the UG and heroic Incursions vs the DZ(for the most part anyway)
The blind chest that I had, I got from the DZ and it was GS268 but had under 1000 armour, vs the blind chest I got in the UG which had 1500 as a base.
I have had a few other examples as well, like strikers gloves from DZ vs Incursions, Predators in UG vs DZ, Firecrest in UG vs DZ where everything but the DZ was better.
Luck of the draw as always but it happens too regularly - only exception to this is Alphabridge so far.
Main reason I say this is that until I went into the DZ I thought that the new GS255 max score, would be a good indicator of the fact the player is pretty well geared as all the pieces I had received in Incursions/UG were all a massive upgrade from 240 gear or the 228GS overall.
But I can easily make myself a bit of a weak fart using some of the DZ 268 pieces (now sold) so there is still no way to tell which is annoying, and also no way to tell until you see them play.
Works in reverse though, I know GS255 doesn't relate to a well geared player but I have seen complaints about people getting kicked to low GS lol. They need to find a balance with GS OR make it so that GS255 is definitively a well geared player, or as a last resort - remove it as currently, having GS requirements on stuff is pointless.
EDIT: Overall, GS268 gear is a massive upgrade though, shockingly so infact, suppose its the RNG at work again lol