Trainerroad with Samsung DEX on smart TV

Does any one use Trainerroad with their Samsung smartphone connected to a TV via Samsung DEX? I currently use a Samsung Tab a7, and whilst the specs are within recommendations, the tablet is quite slow as it’s only bottom-mid range.

My phone however is the latest s21 Ultra, and wondered what it was like running Trainerroad through DEX onto a smart TV. I like the idea of being able to have trainerroad running in one window and YouTube in another.