Re: Verifiable builds need attention. Only 3 of 68 Android wallets are verifiable
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How exactly are you testing Hardware Wallets?I guess you first need to have actual device in your hand (purchased or received for testing from manufacturer) and then try to reproduce the code.
We look at claims about the functionality of the device to see if it falls into any of the k.o. criteria like not having a screen to verify what you approve. Then we look for the source code and the binary. If the source code compiles into the binary, the wallet is reproducible. Check out our full methodolgy.
So ... if you want to help, there is a ton to do from simple triage to compilation to design to spreading the word. 
I am helping in spreading the word about WalletScrutiny and I am monitoring hardware wallet changes, especially if they claim they are open source.You can track that in my topics that is updated on regular basis like this one for example: LIST - Open Source Hardware Wallets.
I think we have all the products you list. We have to review most of them still.