I do use "cute" time to time. Just grepped a bunch of my source tree to find about a few dozens of uses.
But I agree that having two variations of 'is' in a sense of cut/cute seems too much.
What I'm thinking of is this: Currently, 'is' macro has two functions, namely rearranging infix operators and shorthand of creating a closure, which are orthogonal to each other. Conflating orthogonal features doesn't seem a good idea. Every time a new macro that has additional function of the latter, we would go into the same discussion of cut/cute semantics, which symbol to use for placeholder, etc.
Instead, can we split those two orthogonal functions? So that the latter function is solved once and for all.
One way is to define an extension of srfi-26. It only allows <slot-or-expr> in the arguments, so we can't combine it with macros such as 'is'. But the restriction is because of difficulty of coming up a complete general semantics of allowing syntactic keywords in its arguments. It doesn't prevent to define an extension that allows *limited* use of syntactic keywords, e.g. we can define semantics of (cut is ...) or (cute is ...) specifically.
In case if you don't like '<>' as the placeholder, you can delve into yet another sectioning syntax, e.g. Clojure-esque #(is _ < x) etc. In that case, however, I feel it is better to have a separate srfi.