It is time.

[Secrets]

Technically you could easily implement stamina values, even with endurance being in instead. Wouldn't even need a client hack/change for anything beyond stat reductions, sinking to the bottom of the lake when you're out of endurance, etc.

Take the total endurance and turn it into the percentage value you need to simulate classic. The client does its own endurance calculations in Titanium, but the variable is pretty much the same across the board. Send the value of endurance you need based on the server's 'percent' representation. Use that percent for server calculations and gains/losses, but send the actual numerical value (not the percent) of the amount you would be missing from the total.

Technically everything would still work if you did that, ie; jumping, as it does already.