midi fx: 3rd party midi vst plugins in a midi insert slot ?

i want to, for example, use the “arp4midi” (arpeggiator) vst plugin as a midi insert fx in an instrument track inspector’s midi insert fx slot. is this at all possible or must i choose the vst instrument rack instead ? that i know works, but i want to simplify my projects some more…

i know that i can choose one of the arpache arpeggiators as a midi insert fx, this is possible, but now what about all the third party vst plugins ?

Did you ever find out?