Well, there's lots of imagination here. Another that challenges the status quo in a big way gets my approval.
Back on a another forum or two I used to belong to, I was introduce to an idea called "Confederation of States." Basically, it would use a similar strategy as your IRA to get 3/4 of the states to sign up. The basic premise is to rid the Feds of lots of power and let the states make the decisions. I don't see much of COS on Medium, probably because it had a lot of right-wing thinking to it.
The electoral system you have described is very European: proportional representation. It seems strange that you could not use those terms.
Which brings me to a flaw that I am seeing with IRA. Let's consider New York. While the pundits like to call in a blue state, there are still a lot of people of who vote red, let's say 30%. If New York state is given a PR electoral system, the 30% of the reds would get 30% of the NY states in the IRA--and then (supposedly) side with the red rural states. So I am seeing a political force that mostly counteracts anything the IRA could do.
There is a great reason why 48 states do not want to split their electoral college votes in a similar way to Nebraska and Maine. The political players in charge of the day do not want to share their cookies.
Having said that, I am not seeing the EC or two senators per state rules as vastly undemocratic. These antiquated structures may give a slight edge to the Republicans these days, but the Republicans still need to put together a viable candidate and campaign. In other words, if the R's are not viable contenders to the general public, the R's can't win. So in this manner, fixing this imbalance with the IRA is an arrow going to the wrong target.