Pivoting to Max Conversions for B2B lead gen. Should I implement Micro Conversions?

Been trying manual cpc for a b2b lead gen campaign with lackluster results. We're gonna try max conversions. The only question is;

• Do we just use lead forms and calendar bookings as the only primary conversions?
• Or should we add in time spent on page (1 and 2 minutes) as two more primary conversions. We are just now implementing this and didn't measure beforehand. Current analytics shows that time spent on page is currently less than 1 minute.

Thoughts? Anyone have experiences to share with the above suggested method?