IMO this is not a point worth considering at all. If your app fires so many events that just passing arguments via a map becomes a performance consideration, you have a much, much bigger problem.

Do you have an intuition for where performance might suffer? Also, there's https://github.com/day8/re-frame/blob/master/src/re_frame/query/alpha.cljc, which demonstrates subscription queries as maps. A working prototype for event-queries as maps might be relatively easy to put together, based on the designs already in place.

> Do you have an intuition for where performance might suffer? Not on the re-frame side of things. Bottlenecks are in the app code, not in re-frame.