You can put rally parts on a slash 4x4. I seen people convert slash into rally and rally into slash easily.
It's not the radio,.it's the firmware, so it's RadioLinks issue. Not mine. I knew I should have went in debt and got that 900 dollar 10PX radio from Futaba.
When I bought it, RadioLink was a good brand, but over the last 3 months they went down hill as their customer service is AI bots so they only catch key words and don't know what we are taking about. And I been trying to get a hold of a real person and talk them into fixing the firmware issues because it's been going on for 3/4 plus months. Not my fault I can't time travel to the future and see the issues with the radio before I bought it.

So I learned a lesson to not upgrade the firmware on electronics, unless it is a forced update on let's say a phone, smart TV or PC.
Normal price of the 8X is 330 bucks. I got it on sale for prime day for 255. So inorder to get good electronics, you have to pay over hundreds of dollars. Lesson learned. Same can be said with the new rally RTR with the tq radio and slow brushless system. So that's why I been looking at rollers and save money rather than rtrs. Just.my thing but whatever.
If Traxxas didn't exist than I would be a whole lot.nicer.

I got 99 problems but my losi and associated aint one.