I'm thinking about combining a SRAM RIVAL E1 AXS XPLR 13-speed derailleur with a GOLDIX 13-speed cassette that retails for $50 on AE.
The cassette seems to fit on a standard HG freehub.
I wonder is the spacing of the cassette cogs is compatible with the SRAM derailleur.  Does anybody know?

Good idea to use a GX ASX with RIVAL shifters. Just ordered the shifters from two different places, for whatever reason, they only had one hand in stock at 5-0+% discount:)
I'll look at a GX shifter to complete the system.!

 

I am looking for a 1x12 Gravel groupset with Electronic Shifting.  I am not convinced Wheeltop GeX or LTWOO eGR are fantastic from the reviews out there. They could probably use one more design cycle. They are not super cheap either.
But all SRAM or Shimano groupsets are well north of $1000, which seems overkill for my project.
So here is what I am thinking and I would like some feedback.

Magene P515 power meter crankset $299

SRAM Rival Shifter Brake $79 (https://bikecloset.com/product/sram-rival-axs-d1-right-side-f20-950mm-shifter-caliper-caliper-bolts-washers-not-included-oem/)
SRAM Rival Derailleur  $149 (https://bikecloset.com/product/sram-rival-etap-axs-d1-rear-derailleur-speed-12-black/)
This derailleur does not take a wide cassette so I would swap out the arm for a longer arm $52 on Aliexpress
I'd need to find a left Rival brake lever and piston only, don't need any shifting.  These are a bit hard to find in lever only, at least in the matching color it seems. I wonder is the actual lever is handed or if just the hoods are? Does anybody know? Hoods can be found online for $40 and the price for a shifter brake at $79 is cheap so I could just swap the hoods if that is the only thing...
The derailleur comes without battery so lets add another $15 for a AE battery

ZTTO cassette 11-50 $60

Totals to $775 (OK without chain and chainring) for an SRAM solution with a power meter, which I think is decent?

Not sure if all this is going to work though 

Is the new Rotor UNO Gravel groupset (https://rotorbike.com/en-us/uno-electronic-gravel-upgrade-kit.html?utm_source=criteo&utm_medium=display&utm_campaign=Retention&utm_id=487265&cto_pld=vAg5WbbOAQAg_ovdXUy1uw)  in fact just a rebranded Wheetop EDS GeX, or is this actually something different?