I would imagine the "Bludgeon effect" would more relate to toys that don't have an important function/rank/bio gets given centre-stage treatment... similar to toys that have leadership functions, or, just big massive toys that Hasbro demands comics & cartoons to feature, just to sell the potential loss-inducing shelfwarmer.

That particular definition will help narrow down a list of candidates, that at the time of their toy's release, would have been an unlikely choice of playing centre-stage in the comics & cartoons, based on the toy's bio or size.
The first season of the cartoon allowed for a fair bit of character-centred episodes, but in general we had, 1984 Bumblebee used a fair bit in the comic and cartoon... for someone who was just a minibot and a function of espionage.
Blaster got a fair bit of attention, but was a large toy, so doesn't count.
Wheelie was featured in the 1986 movie, and in the JP Headmasters series, but was just a minibot, so does count.
Ratbat got a lot of attention in the comics as a leader, despite being just a cheap cassette, and a function of fuel scout and rank of 6... so counts.
Bludgeon was a Furman favourite, and a leader for most of his comic life, but was just a small-scale pretender, with a function of Electric Warrior and rank of 6.
Beast Wars Rattrap & Terrorsaur - the BW cartoon had a limited cast because of the huge cost at that time for a fully CGI cartoon, so it was odd to have it promoting two of the cheapest toys, when there were other more expensive toys that should have been prioritised (Polar Claw & Buzzsaw). The cost and (spring-loaded) gimmick of the Basics would have sold themselves, so why include those two?
Airrazor was a Basic too, but would have been included because it was the only flying Maximal toy, which opened up more story potential... but Rattrap and Terrorsaur would never have been popular toys if it weren't for the cartoon, because they weren't anything special.
From the Transmetals, Fuzors & Transmetal 2 years, almost every large-size toy was included in the Beast Wars cartoon. Quickstrike was the only other Basic included, but possibly because it was the best looking Predacon Fuzor, to help sell Fuzor toys.
In Beast Machines, the toys that were Voyager or larger were all in the Cartoon, and the few Basics in the cartoon had larger toy versions released.... which essentially followed on in every toyline after that (small cheaper options of large in-show toys).
Yellow characters seem to be a popular choice in TFs cartoons, most likely for standing out visually, to stick in the minds of the kids and sell the line through association.

Cult figures exist as well, like Dispensor, Erector, Cannonball... but as noted by others, they are usually after the toyline is over, and the characters spawn future homages based on their cult-fan status.

What other small, insignificant toys were given star status in cartoons and comics, to prompt people here to buy them... toys that would otherwise be ignored if it wasn't for their significant role?