The SRFI claims that since the R6RS/R7RS small exception system already deals with establishing a stack of exception handlers, a separate stack of restarters is no longer needed.

I think this is incorrect. The R6RS/R7RS small system doesn’t give you any way to immediately get the full stack of exception handlers in effect at the point raised; you can only dynamically invoke them one after the other. So there is no way to install a restarter far up the stack and have that immediately appear as a recovery option at the immediate moment of an error. In particular, the ‘ambient restarter’ functionality of the original SRFI and pre-SRFI is gone.

I assume similar considerations are why the current-interactor parameter of SRFI 249 was also removed. I think this should be restored as well.

Daphne