I’m going to have to disagree with the people above me, and say that I would like Bakugo we have OFA permanently, but only under certain conditions.
Firstly, I wouldn’t want Bakugo to have all of OFA. They would have to split it.
I’m not sure how Horikoshi could write this into the Manga, but as the OP says, Horikoshi has definitely been thinking about this for a while.
Look at these two color pages for example.
In the first we see All Might with a large sword which I believe represents his power. In the second, Deku and Katsuki both split the sword. Which I think represent splitting All Might’s power.
I know that some will probably say that the sword doesn’t represent All Might’s power and is more metaphorical. However, in the first Deku does not have is gloves, and it the second - which came out right after Deku learned Air Force - does. So, I think the clothing in the cover represents power. Even more evidence. In the first image Deku has no weapon, but you can see the hilt of Bakugo’s dagger. In the second Deku has his inherited sword and nothing else, while Bakugo has the inherited sword and his dagger. This represents his explosion quirk, and Inherited OFA.
If they do split OFA, I can imagine Bakugo getting the two quirks of the two shadowed predecessors, and maybe 40% of the stockpiled power. While Deku would keep maybe 60% of the stockpiled power and quirks of the four clear predecessors.
This way I can see Deku surpassing AM and being number 1 with 4 quirks, Katsuki surpassing AM and being number 2 with 3 quirks, and Todoroki surpassing AM and being number 3 with 2 quirks.
To be honest, with 6 quirks and 100% OFA Deku would easily surpass AM with no challenge, and neither Todoroki nor Bakugo would be real rivals.
I feel like something like this would make things more interesting.