@Solv777 others answered everything 🙂 sorry for late reply.
Yeah, basically you set it as single part (or batch of them... let's call it part, just for the sake of simplicity) in slicer, then you set that to be printed with multiplication tool. That is set similar to a single tool definition, but you'll set additional tools like T4 to be a duplication tool (for like front two), T5 to be a quadruplication tool..
You place your part to be printed in the middle of the bed and firmware will take care of offsetting and multiplying it based on offsets set in config.
You've probably found "Marx group" on Facebook. I've shared my configs (top most post, links to google drive) ; https://www.facebook.com/share/qNYUQoUD2tn3p4hP/
As for slicer, you can use whatever you're comfortable with as long as it can inject stard and end g-codes.... So really whatever you're fond of most 😉
As you've got the info above, you can stop specific one of the head printing using extrusion factor, should one of the copies fail during print.
I've even printed TPU, PLA, PVA and PETG in one job, each copy being it's own material since one can use individual Pressure advance factors on each individual extruder. It's a long ago. Was featured on one of E3D's facebook groups/pages.
Also, set both left toolheads as one tool and both right toolheads as one tool. This will enable you to do a duplication of dual material printjob. Because you can.