Yeah... I will most likely invest the time and money to build a seedsigner. Good thing that AirGap Vault works for my immediate needs. Thanks in any case man! =)
Welcome. You are likely greatly overestimating your threat level. Hardened Android in airplane mode is totally fine. $300 you put into building and configuring your own wallet is well worth it in terms of gained skill. The scene needs more physical projects like that instead of another bullshit service for speculation