I'll have to live with that 1000uf cap. There's also a 22uF cap by the C4S boards. Is that in the signal path? I'm unable to review my manual for some strange reason.
The 22uF cap is pretty well isolated by the C4S load, though things like this are "supposed" to not make a difference, reality seems to say otherwise.
The 1000uF/35V has some substitution options, there's a Nichicon 1000uF/25V ES, 1000uF/35V FG, 1000/35 KA, 1000uF/25V KZ, etc.
One can drive themselves insane trying to pick these things...