Can an eventing horse do western trail riding without confusion?

Hi, thanks for using Petco Pet Education Center, formerly Petcoach. It should be fine to use a western saddle on Lexus. The more diverse a horse is the better. Just be sure that your cues for walk, trot, canter, stop etc are the same. I would not try to change her head carriage or way of motion though. She does need a different gait if you were to do true western pleasure on her and that may confuse the training she already has in place.