Ya, redundant connections between two switches gets complicated somewhat quickly. If you are willing to use routers, cost goes up, but there are some more options and a bit more control. Might be easier to make something that works, but then again, you are stuck using routers and that creates other management difficulties.
The issue is that Switches don’t have any concept of TTL (Time To Live) like we do higher up in the OSI model. So you need to build around that.
Yes the B5/B5c can do this, but they basically have a network switch built into them (Not really, but in principle that’s kinda how it works out if you really want to pick at it.)
TBH there are a hundred different ways to do this, but they boil down to requiring some level of network expertise to get them setup right. You might try reaching out to IPArchitects and see if they have something that they have used in the past that is stable. I would offer my services, but everything I have built requires some level of user interaction or has shortfalls that wouldn’t work for you. (Sorry, I just have not been paid by anyone to do this exact thing so I just don’t have something up my sleeve.)
The other option would be to utilize different hardware. The B24 isn’t nearly as effected by weather as equipment that uses 60 GHz is, though price is kinda high… Another option would be to use a 60 GHz solution that had a 5GHz radio backup built into it. Both Ignitenet and Ubiquiti have products for that. TBH Ubiquiti’s AirMax 60GHz probably would be your simplest solution.