The real issue with blobbing is the underperformance of some anti blobbing assets.
The problem here is that whatever buffs you give to individual units/abilities to make them better versus blobs will also make them better versus individual squads. The old demo is a good example of something that was a great deterrent to blobs but ultimately also caused too much inbalance to individual squads.
On top of that not every faction has access to good anti-blob units, such as Ostheer's Brummbär. OKW for example has nothing except the generalist Panzer IV (Stuka sucks vs blobs) and arguably the Sturmtiger. Those that do have these units locked behind late-game tech (Katyusha, Brummbär) or doctrines (Pershing, AVRE).
As long as the game has no way to distinguish for units/abilities whether they are targeting single units or blobs, I think the only way to nerf blobs is by giving them a RA/RD penalty. Therefor I voted yes. I'd give something like -10% for every squad in close proximity of one another, with a minimum of 2. So 3 squads gives -10% (not gonna hurt too much if you're forced to briefly blob due to map or circumstances), 4 squads give -20%, 5 squads give -30%, etc.
Perhaps the incremental accuracy mechanic for HMGs can somehow be used in another way so they can deal more/faster suppression to bunched up units, but I have no idea if that's possible.
P.S. the HMG 34's suppression profile is only 10% worse than the HMG 42's. Which is still very high (~2,33s to suppress at 30 range). It's its DPS that is lackluster.