Thanks for the detailed reply.. :)
the lack of available and reasonable options for replacement tanks
I thought about that, and went ahead and ordered a spare tank paired with the worthless DT from another place for around $6.00 USD after I purchased the 1st E3. I didn't know I would enjoy it so much, and in hindsight, would have just been better off to grab 5-6 of the complete RTA's at the sale price for complete spares. As posted above, I did get 3 more for plenty of spares and extra tanks if needed in the future. That ends up being 4 decent MTL RTA's for about the same $$ as what one would pay for a single comparable one.
Edited on 2/25/2021 at 9:00 AM. Reason: