Are there any other alternatives that are easy to use with accuracy maps (or a group-level t/z image)?
Last I checked (a couple years ago), cluster correction of searchlights does not have very user friendly tools, and you’re probably going to be stuck implementing some of it yourself. The canonical paper I would recommend is Stelzer et al (2012) (summarized well and linked here). It’s probably worth searching for more recent papers, though.
Additional discussion of this problem here, where I dug up some code to implement an adaptation of the Stelzer approach: Cluster correction for partial correlation on searchlight map