I want to change my beard texture with transplanted scalp hair, will this work?

It’s an interesting idea, and yes, theoretically, you can alter the texture of your beard by transplanting scalp hair. Scalp hair is naturally finer and straighter than beard hair, so if you were to undergo laser hair removal to remove your current beard and replace it with transplanted scalp hair, the new hair would reflect the texture of your scalp.
However, it’s important to keep in mind that while the transplanted hair will have the characteristics of your scalp hair (straighter and less coarse), it might not grow exactly the same way as it does on your head due to the different environment of the face. The facial skin and follicles could influence how the hair behaves slightly over time, but overall, the texture should remain closer to your scalp hair.
This approach would be a significant commitment, but it’s theoretically possible to achieve the fuller, straighter beard you’re aiming for with the right planning and technique.