I don’t know the dx8, but if you have enough channels for arm switch, mode switch (acro, angle, horizon) and two spare for other betaflight/triflight mode functions, it should work.
That being said, the taranis and other open tx transmitters opens up a lot of options that older radios don’t offer, such as telemetry, Lua scripts, etc. I rely on the taranis functions to call out battery voltage warnings and timer values which leaves you free to concentrate on the flying and not having to look down at your transmitter.