Folded monopoles (I am not sure whether this = cage antenna, but fear not) are often used by b/casters whenever they want to use the tower for their VHF-FM antennae on top thus saving costs for a separate tower exclusively for those VHF antennae.
This is not entirely impossible with ordinary monopoles, also known as plain verticals, but refined requirements are needed.
As for a ground system, both folded monopoles and plain monopoles *need* good grounding, typically in the form of 120 radials scattered around the base.
I have seen folded monopoles on top of insulators, but I'd say the typical ones don't need those.
Appreciate all the advice and options here. Going to have to look into each, test them out on a small scale and see what works best, but thank all of you for providing some much-appreciated resources.