. . . Can you follow up for a third attack if you roll the follow up icon when doing a follow up attack?
This got clarified in one of the earlier updates (Chapter 1 cards). Things like Follow-Up will now typically have a number afterwards in a parentheses to say how many times you can trigger it in a single action. If there is no number shown then it’s always a .
JimmyW has it correct. Follow Up was one of the Keywords that has updated in the Chapter 1 Rules Update Cards (came with the Chapter 1 card pack). It was dated during April 2020 and included them as part of the Limited Use Abilities.
Limited Use Abilities are Keywords, Perks or Special Abilities that are followed with a square bracket. The number in the square brackets is the number of times the rule can be used.
Unless a rule states otherwise, the number of uses you get of an ability defaults to per activation.