In that case, just add a flag (default "on") that enforces this new system, or a command line thing to turn off the restriction, or something. Most users don't know the difference, but it's a big pain in the patootie for me. I only host, so I'm not scared of anyone screwing up my crap with crap-ons; even if I chose to look around the internets, I could switch the flag back on.
ALSO: How am I supposed to load custom save data? Rise of Blockland relied on a huge amount of save data dumped into files that could change at any time. If I can't access those, what the hell am I supposed to do? Change the .zip every time I close the server (which is at least daily, since I can't leave my machine on)? (see my next reply)
This update has done a ton to try and kill creative scripting (let's not forget that we can't set shape names or edit the player list anymore, things that had perfectly valid uses). My point is: Fix the security issues, but don't castrate scripting. I'd honestly rather my Add-Ons folder got flushed clean by a malicious script if it meant I could have the old method back.