That's what I mean. I hardware wallet along with an offline device to create the transactions. But maybe thats a total waste of time.
Discussion
Sounds confusing. If you keep your wallet offline and you use it to create transactions what is the purpose of another device? All you need is the mk4, a micro sd card & a laptop. I have no idea what you would need a Raspberry Pi for.
Being extra paranoid about creating psbts and broadcasting it with a single portable device smaller than a laptop. Its just to use the device for that one single purpose. But yea you're right its a bit redundant.