The PokéRide script isn't updated to v18, and I think Let's Go had a better alternative to HMs anyway. The Secret Technique feature was the closest in my opinion to the perfect field move system. You didn't need to waste a move slot, but you still got to use your own Pokémon to clear obstacles instead of using one owned by another Trainer. The only thing it needed was the ability for all Pokémon to use them, instead of being limited to Pikachu and Eevee. I'd love to implement such a feature in the game I'm making, but I know little to nothing about scripting so I'm unable to do it