honestly the number thing gets talked to death but nobody mentions the first hour after a pin goes out. thats what i watch. if a fresh pin gets a couple saves early it snowballs, if it sits flat for the first hour it usually stays dead no matter what. so id rather post 4 pins at times i know my audience is actually scrolling than 8 spread evenly across dead hours.
the fresh pin point already got said and its true, but one thing... dont just swap the image and keep everything else identical. change the title, tweak the description, different first line. they look at more than the image now. straight image swap with same text still gets flagged as recycled in my experience.
also idea pins vs standard is worth testing per niche. some accounts i run do way better pushing 2-3 idea pins and a couple standard, others idea pins do nothing. no universal answer there.
and yeah agree on easing new accounts in. i treat the first month like a warmup, low volume, no links even for the first week or two just to build some trust before i start pushing traffic pins. impatience kills more accounts than volume does tbh.