Hey Max, what do you need this for exactly? I've been meaning to get to this since I started working with cyclone, the idea then was to clone tapin~/tapout~ but the same design seems complicated for Pd as I discussed in other threads.
So, I made changes to delread4~/delwrite~ that allows freezing, but I already have 2 delay externals in ELSE, and I should "freeze" them too.
I have [ffdelay~] and [fbdelay~] (feed forward and feedback). These are single objects so you don't need a "write"/"read" pair. For feed forwarding delay, that's just fine, the problem with [fbdelay~] is that you cannot put anything in the feedback loop, for that you need a pair like tapin~/tapout~ or delwrite~/delread4~ and put other stuff inside the chain.
So I ask why you need this for cause if it's for feed forwarding or simple feedback (without putting anything in the feedback loop), my existing externals would be ok for you now. I'll focus now on how to freeze them now as well.
cheers