Overcoming the 120% Rule by Upgrading Panel to 400 Amp but Keeping Service at 200 Amp

So...like everyone else I was first thrilled about the prospects of DIY solar, then bewildered by it given so many complexities.  I've actually figured almost all of them out with study.  One of those complexities or really limiters that I ran into as a DIYer and for which I cannot find an elegant solution (like having fun with a drug that won't also make me sick) was the limits of back feed on a bus in the breaker panel, given the good old 120% rule.  Sure you can do a line tap to get around the 120% rule, it but that approach presents other issues including costs, complexities and limits.  Sure you can derate your service breaker to be able to back feed more amps onto the same bus bar, but of course that has its issues.  So neither of these approaches is elegant.

So here's what I'm thinking to get around the limits of the 120% rule on a 200 amp service panel when I need to output at least 126amps from the combined AC output of 2x Sol-Ark 12K inverters into the main panel and at the same time not violate the 120% rule on a 200 amp service panel which limits me to only a 40 amp back feed breaker.  Okay, I'm not really getting around the 120% rule here, I'm just making it work without upgrading my service to greater than 200amps or derating my service breaker or doing a line tap.  Here's what I'm thinking as an approach and I need your feedback of why it will or won't work or meet the NEC or Southern California Edison's requirements:

1. Keep the 200amp 240v Single Phase service.
2. Change the breaker panel to a 400amp 240v Single Phase panel (not increasing the service from the Grid, or the service feeder breaker from 200amps, just changing the bus bars to support 400amps);
3. Install a 200amp service feeder circuit breaker on the 400amp panel which will limit current flow in either direction from or to the Grid through the bus bars to 200amps;
4. Be able to back feed from the inverters via a back feed breaker 200 maximum amps back to the Grid.  That is to say, at no time will the back feed through the 200amp service feeder breaker on the 400amp panel be greater than 200amps.  And, in this configuration the total amount of amps on the bus bar could be 480amps (relative to the 120% rule).

So, with the above setup.  I could back feed the 126amps or even up to 200amps if I added more inverters without violating the 120% rule and not exceed the service feeder conductor limits of 200 amps.

Only problem is - I don't know if it is allowed by NEC code and/or whether SCE will allow me to do it.   Thoughts and assistance appreciated as this seems pretty straight forward to me and less expensive than upgrading both the service and panel to 400amps (as I'm just upgrading the panel to 400amps to be able to back feed as much as possible up to 200amps on a 200amp service).