silverhead

The scope of HX Stomp midi capabilities is described in the manual. There’s no mention of anything like you want to do.

HX FX will respond to any device that sends it appropriate midi commands, as defined in the midi section of the HX FX manual.

No, Helix Control is not able to control the HX FX device (or anything other than Helix Rack).

There are three ways to provide power to a Variax guitar’s modeling electronics: 1) A VDI cable connected to a compatible Line 6 device. You mention that this method is working for you. 2) A standard TS mono guitar cable in the 1/4” output along with a charged battery in the Variax guitar. 3) An external Variax power supply. In this case you need to use a TRS cable in the 1/4” output. The ‘R (ring)’ contact supplies the power to the guitar.

No, that’s not right. Your external speakers need to be powered.

POD Go cannot control Powercab speaker selection. You must do it manually.

I have used both my older Variax 300 model and my JTV-59 with my POD Go, connecting using the 1/4” Variax analog output. I have experienced no problems. Everything works as expected.

This is proprietary information. The only people who should have it are Line 6 and their authorized service centres, and they’re not going to provide it to you.

Any DSP benefit to the HD Bean in terms of processing power because of the things mentioned is probably more than offset by the increased power of the ProX compared to the Pro (and Bean) because of the upgrade in chipset with the ProX (and not Pro or Bean). Overall I think the processing power difference is marginal, one way or the other.

The more disturbing part is the implication that someone else beat him to it.

No, not at all.

Yes you can do that. Just run HX Edit on your PC using your account, with her LT connected.

Unfortunately there's no global setting to have both Mic and Guitar inputs specified for all presets. You have to do it for every preset. However, you can make a template preset with the inputs configured and then copy that preset as a starting point for all vocasl + guitar presets you want to make. Here's a candidate for your template preset. It's designed for an acoustic guitar+ vocals but easily modified. https://line6.com/customtone/tone/2044875/

See Global Settings -> Footswitches. Knob 3 - Preset Mode Switches (manual page 68)

Define ‘popular’. ;-) More than1? Yes. The majority? Probably not. Somewhere in between? Probably.