I don't know about a downscale, It's pretty much cut and clear that a Goblin Bomb is capable of damaging Giant Sandman and made him scream in pain, and these guys like Tobey Spidey could harm those who can survive Goblin Bombs at point blank range (New Goblin) and even survive one himself, He can even tussle with Doc Ock's arms somewhat and take hits from it. also Tom's Spidey can survive a point blank Goblin Bomb explosion as well.
Also Sandman's AP when Giant is 8-B and my guy was literally pummeling Tobey Spidey while he was being pinned down by Venom, yet was still able to get up in the end after taking so much punishment.
Also there's that one 8-B Calc with Raimi Spidey holding up the warehouse wall but I feel like that needs to be changed up a bit, and I don't think it was approved on site as well so what ever.
Webb Spidey could take in Electricity from Electro but he was wearing some insulation for that so hmm.. Though he managed to take in Electro's physical attacks as well in that final fight.
The reason why it will probably be hard to prove is because Electro's rating is hard to know when he is using his High 8-C+/8-B power or some shit due to the nature of how the values were obtained while there are fodders like Captain America trying to squeeze in on the fun of scaling