I’ve long had house rules for classic/revised where each nation has a nation specific ability. (not necessarily a technology.)
Like Russia could buy infantry at 2 IPC each but could not leave Red territories.
America could rebuild any sunk ship or shot down plane at 67% cost.
Etc. (German tanks attacked at 4; Japanese Infantry attacked at 2 during an Amphibious Assault.)
But in this case, H. Bombs are not really broken, they just seem disproportionately powerful for the cost of a bomber. (They are not broken because both sides can get them and thus be equal.) Perhaps if a bomber cost 20 IPC like a battleship it would be more appropriate for them to get a major upgrade like this. After all, bombers cost 12 IPC, attack at a 4 (or 2@4), can move 6 (or 8) can potentially carry infantry to attack long distance, can attack land, sea and industrial complex.
If they cost 20, then that would be stellar, that would be akin to the battleship taking two hits to sink.
I guess either I should go with above, or increase the price of a bomber to 20 IPC (which is WAY doable in 1941. When America and Japan are potentially earning 60-90 IPC, they can both afford to drop coin on a 20 IPC bomber! Likewise Geramny can too, with their 50-60 IPC, considering I routinely buy two bombers with Germany and not have a problem/that’s in a single round btw, not two different rounds.)