Starting in 2021 the bed cubby of the 400 has a combination 120v/usb outlet. It is hard to see on it in photos but what looks like just a 120v outlet actually has two usb outlets in it as well.
If boondocking the inverter must be turned on to operate the 120v and the usb outlets. If on shore power it will operate without the inverter needing to be turned on. There is no longer a 12v cigarette style outlet in the cubby.
So @DaveC look closely at your outlet. If you only need a USB it should already be built into the 120v outlet. Here is a link to NuCamps walk through of the 2023 400. At about 5:40 in they show and go over the features of the bedroom cubby, which includes the combo 120v/usb outlet.
That plastic connector seemed like the Achilles heel of the Nautilus so I installed a brass connector with a shutoff valve on the end of it. That way the brass valve would take the majority of the west but there’s still the chance the plastic threaded piece could break.
My 2015 320 has an 11 gallon fresh water tank and a 19 gallon grey tank. I typically start with a full tank and add fresh water every couple of days, trying to keep track of how much I put in so I have a rough idea of how much is ending up in the grey tank. I don't have tank sensors so the stink water bubbling up through the shower drain is my only indicator that the grey tank is full! :-O
I think there are sound bars available for the TV/monitor. Blu-tooth is not a bad choice either.
For streaming movies or watching DVD's we picked up a cheap sound bar from Amazon. I doesn't sound bad and is much better than being blasted in one ear from behind. I used the optical output from a HDMI audio extractor to get sound to the bar, but it will also receive a Bluetooth signal . Very happy with the 27" Samsung monitor.
Just tested and everything is working like it should. Thanks to this group for the tremendous support. I know we've learned a lot about the Alde system.