I don't know how Diku works exactly as far as the way things repop, but another thread inspired me to wonder - could plants be made to slowly repop their contents over time, in addition to normal reboot repop? For example, a bush that contains five piles of leaves maybe regens one pile of leaves every couple IG days, up to its normal max of five.
In a similar vein, perhaps shops could slowly deplete their non-permanent stock over time, perhaps in proportion to the cost of the item (i.e. more expensive items take longer to deplete). This could reflect the VNPC market forces, perhaps.
The first one I'm almost positive I've seen before, at least in one place. Not certain, but pretty sure.
I would rather plants pop less 'plant parts' more often.
There is some plant code in place, which Nessalin wrote a few years ago, although we should probably go through and look at the plants in the game to see what's using it and what's not.
There's also something kinda sorta but not really what you're talking about for shops.