I have a little bit of everything in my tank and IMO coral placement in a mixed reef is very important for lighting, flow and growing needs to limit fighting and competition. I run carbon, phosban, purigen 24/7 along with weekly 10-15% water changes and skim wet to help combat nutriant, toxin and chemical build up.
Monti digi are fairly tolerant to lighting, but I find that the purple need stronger light to maintain that color.