What is the appropriate plane placement for Ergonomix implants?

I'm a low BMI, low breast tissue patient who priortizes implant longevity and am interested in Motiva Ergonomix 275cc moderate profile for a natural look and feel. My surgeon is suggesting a modified submuscular placement with 90% muscle coverage. Rather than a traditional dual plane with full inferior muscle release, we would retain some muscles to create a sling or internal bra. I like the concept, but just want to know what other surgeons think. Also, is Ergonomix more difficult to place than round and anatomical implants? this surgeon's clientele doesn't request ergonomix often, but I really like his breast augmentation outcomes otherwise. Would his skill with other implant types transfer to Ergonomix?