I am very tempted to tell you to stick with the UD and get a DC power supply as mentioned above. I think this is probably going to be the best scenario for you. Tried and true, but now on batteries with minimal additional cost
Don't go with a GH yet, I'm as eager as the next guy to get a working one of these into my hands as a sole daily driver, but there is a reason I've not done so.
I am not confident that a grasshopper is going to work without failure/problems in a sole vape/daily driver scenario. You need backup vape/s if you're buying a grasshopper in case you encounter one of the known issues (which hopefully will be resolved sooner than later).
A minivap would be a fantastic vape to connect to glass in your stated home portable scenario. It is big, but this doesn't seem to matter for your needs. It delivers the juice IIRC and I'm sure this would be attractive as you'd wanna minimize how often you need to charge batteries!
You could get great results with a Mighty too. Still, I think you'll find that these options will be a lot of additional spend and may not suit your needs much/any more than your trusty UD with a DC battery pack.
Butane vapes really don't sound like what you're after as it seems that avoiding the possibility of accidental combustion is a high priority. You may find you prefer to use your UD with a DC pack over the Lotus when away camping in future because you'll be able to dial in a non-combusting temp more easily! I used to own a Lotus and loved it (especially for the effects, taste and clouds at the pricepoint when done right), but the accidental combustion risk especially when very medicated was a PITA.
I don't know if the FF2 has a WPA, nor can I speak to it's performance so I can't say either way if it would work well for you. Might have a look at that one myself!