Aerodynamic efficiency of different gliders
With the introduction of aerodynamics, all gliders are currently performing the same as their simulated shapes and sizes are all equal.
For starters, gliders should each have their own dimensions, and possibly different shapes as well, e.g. elliptical, tapered, delta, and other properties like sweep angle.
I'm somewhat confident that tapered wings can be modelled. Less sure about delta wings. Wing sweep is technically accounted for already, but not used (nor tested).
If the modelled properties are remotely true to the item's in-game model, many gliders will become quite.. underpowered. This may be acceptable to some degree, provided new, more aerodynamically efficient gliders are added over time as more valuable items. Then the older, less performant gliders could become lower quality items, delegated to be used for visual flair more than practical use.