I don't know for sure honestly, because I am at the opposite end, I rarely make changes to my gig. I just change my gigs when I need something changed, Sometimes changes are significant, other times are not.
The idea is, I just change when I really need to change something, I don't make artificial changes thinking it will boost search results ranking. There are things like reviews, both private and public, if you cancel orders, etc. For new sellers, Fiverr promotes you high in search for a while, and you receive messages, eventually others take your place and you have to promote your gig yourself.
Do whatever you want, ideally I would create multiple gigs that I am just very good at and track clicks (not impressions, maybe check impressions just to see out of how many people see in search, how many of them click).
