I see various suggestions online of MaxRequestWorkers appearing in either <IfModule event.c> or <IfModule
IfModule mpm_event_module>
No difference between the two.
Wrapping it in any ifmodule at all: Only if you'd ever use the config with another MPM _and_ want the value to differ. For example, if you waffled between worker and event and indeed more threads w/ worker since none are offloaded.