I dont think your going to find a keyboard thats is off the shelf that fits all those requirements. Besides the Advatage 360, theres the Dygma Defy for 500 USD (with all those extras you want, 325 with no tenting and wired, and its not coming out anytime soon). You can go to Esty and search for a "dactyl manuform"

Thebigskree (https://skree.us/) ~350 USD, Is wireless, hotswap, but not RGB, but the pcbs seem to support it. Going to have to contact them. RGB sucks up the battery fast, maybe thats why the option isn't available.

Cyboards ( https://www.cyboard.digital/ ) 245 to 385 USD, depending #keys, has RGB, but not wireless.

Wyderbuilds (https://wylderbuilds.com/shop/p/dactyl-manuform-build) ~ 300 USD, RGB, hotswap, not wireless.

Theres not alot of readily available wireless ergo keyboards. Gonna have to ask yourself do you really need it? If you drop the wireless requirement, you'll have Way more options, or go DIY.

https://ergomech.store/ Solfe RGB

https://keeb.io/ - Iris and others

https://falba.tech/ - Wireless splits available, not so sure about RGB options, if any.

Hope it helps.

What are those pudding keycaps? Looking to buy some.