Seems like 1 offline computer and 1 online phone would work just as 1 offline computer and 1 online computer.
1 offline computer and 1 online phone is better suited whilst travelling.
Therefore, I'm wondering with the send transaction, how as currently my offline computer TailsOS USB Electrum says no funds, but I have successfully received funds to the offline wallet.
The offline wallet doesn't update the balance, however the online phone mempool shows the balance update.
I'm trying to adapt this video
https://www.youtube.com/watch?v=DQumISxkJsQ process, but I guess the online phone which doesn't take USB sticks, would either use a QR scanner or I would have to manually type some details into the phone's online hot wallet (it's an iPhone, so no Electrum app).