While I acknowledge and appreciate the difficulty of managing everyone's satisfaction on a platform like Fiverr, from a seller's POV here's my 2-cents...
I feel this may be abused by the buyer and agree it should be a decision between buyer and seller.
Modifications can throw my timeline for other projects off - this impacts my ability to maintain an efficient schedule when the revision timeline could require attentiveness and promptness for a longer period.
I am also confused when the buyer modifies close to - or now after - the delivery date and red letters are warning me that my delivery is now well past overdue.