The approach does work.
From the offline setup I sent myself a small amount of BTC.
When the SSD was returned to the online computer, it caught up. The sent coins have been sent and subsequently received.
Apart from the potential inconvenience of moving the disk containing the blockchain between the 2 computers, it's very simple, and it works.
If I understand you correctly, Im not sure your system will work, because your air-gapped laptop is never connected to the internet, the transaction wont get broadcast. You can try it, I may be wrong.
I have done a similar process using rawtransactions, where you prepare the rawtransaction on an online computer, using an explorer API (https://chainz....
The only thing you need to spend bitcoins is a Private Key, I recommend that you create a Private Key beeing offline, then import it to Bitcoin Core wallet or Electrum Bitcoin wallet (if you don't want to download the complete blockchain) these are the most secure protocols.
First you need to create a Private Key, it consist on a 32 byte array on HEX format(...
Download latest BTC client
Move to a pc not connected to the internet.
Create an address on that PC without internet.
Send fund to address created on PC with no internet access.
Save keys in safe place