Tally and Talkback with non Black Magic Camera

We have a ATEM 2 M/E Constellation HD and 3 Canon Camcorder type cameras each with a Blackmagic Video Assist 7 3G screen and SDI connected to each camera location. What is the best way to get tally and talkback with this setup? Would running fiber to each camera and adding an ATEM Camera Converter into a ATEM Talkback converter or ATEM Studio converter work? Thanks!

Yes U can use BMD sollution or something 3rd party .. It depends from your needs .. Do U use OBVAN and long cables ? Or do u have gears in Venue ?

3rd party things :

For Intercom there is lot of things .. For example Hollyland have lot of models :
https://www.hollyland.com/product/mars-t1000
https://www.hollyland.com/product/syscom-421s
Or cheapest is Eartec :
https://eartec.com/shop/

For Tally there is lot of things .. One fine is cerevo FlexTally :
https://flextally.cerevo.com/en/