I think this wingfoil leash can be also be good for eFoilers. I hate it when a leash is in my way on the eFoil board, looks like a good solution.
This retractable leash is quite cool. My next Christmas present 
There is also a solution for your leg:
Yes, eFoilsolutions does great products. E-SURFER is partnering with Jeff since a few years and is exklusive distributor in Europe. eFoil carts, negative shims, axis adapters, the list is long…
I am especially happy about the leash and so are others:
