You can spray on the 215ic.. All he has to do is use the 93 percent argon mix with a 0.8mm wire and he will easily get full fusion on a 5mm plate rather than risking it with Dip transferThe OP has said they using an ESAB 215ic, not a 235, plus it’s 5mm not 8mm.
so I’m guessing that machine is pretty much short circuit only, a higher Co2 content would help with penetration in that case. Don’t think anyone has given any BAD advice in this thread, only advice based on the info given.