I am sharing my point of view, Sellers need to Avoid Order Cancellation Because Its effect on gig Search result in fiverr and may be in Ranking.
Sellers need to write gig description very clearly and mention Important Note too For buyers, Buyers also need to review carefully GIG description before placing any order.
So, buyer and seller understanding is much better.
And Sellers need to Do Work as per service description of the gig, and Try to Avoid Order Cancellation, to make trust and position in fiverr. Thanks