Soulmates

On Flysky have noticed that once binded flysky will only speak to that controller and no other, soulmates. I would like to use the smaller 7e in addition to the bigger controller (9xr pro) depending on travel
arrangements. Not a problem with the dsm or devo receivers, is frsky the same? Can that unwanted feature be disabled if you don't need it, on flysky and/or frsky? I LIKE THE RANGE AND PRICE of flysky
but don't need that particular security. I changed from the 7e to flysky & frsky because of the range(failures. crashes), the native 7e dsm/devo has disabled power, question is should I be looking back to dsm/devo.
Would I get the same range as flysky and frsky? Are we good now with the 4 in 1? And by range I mean in a 2.4 noisy (home wifi) environment, having the $ invested to photo/video for business use of surveying,
exam type of houses for insurance companies, along those lines.

FlySky is used by a large number of toy companies, and the different implementations behave differently. Some will bind to a tx as you describe, others won't, and have to be rebound every time you fly them.

The DSM protocols have to be bound, but many of the flight controllers with an integrated Rx will time out if they can't connect to the Tx they are bound to and go into bind mode. This makes them work like the FlySky models that don't bind. Stand alone Rx's tend to only bind with a bind plug inserted.

Devo does both. Rx's will work without binding, and automatically connect to any available tx when they power on. But they can also be bound, in which case they will only work with the tx they are bound to until you clear the binding.

FrSky works like DSM, except the Rx's have a bind button instead of a bind plug or a timeout.

I don't believe there is a reasonable way to make any model bind to both a 7e and 9xr. There is a txid used for binding that is generated from the RF module. With deviation, you can set the txid in tx.ini and have two deviation txs that work with the same bound model. The 9xr leaves binding up to the RF module, so can't do that. Which leaves you trying the over 65000 possible txid values to see if one of them will work.

The DSM/Devo range issue on the 7e is tied to that RF module. Replacing the RF module like with the 4-in-1 solves it.