Send 3 times. Check the last two messages (first trains RF). If in doubt look into forward error correction. Sorted.
The counter argument is that bits are power - If power is an issue then just add a solar panel - he's low volume.
A company may prefer cost but would have the hours to burn.
Well old school slow 1970's RS232. Its the upper limit that matters. Choice any bps the UART offers below 2048bps IMHO. I suggested 1024bps. I doubt the UART would work though.I'm guessing all those speeds are RS232 and similar.
I have never needed/wanted to go above 1024 bps. All that I have read says that 2048 is your limit with the cheaper RF modules & if that's the supposed limit I would use 1/2 that for starters. You just cannot tell with commercial cheap.
How many sample devices did the github/wiki man use? I'm guessing one for a few minutes & then he boasted
Good luck, its a great project to do from first principles.