Your not the only one with this problem. Triathletes tend to make up most of our team, but in my case our coach has given us 2-3 days, 3 lanes out of our 6 total lanes for stroke work. Usually Tuesday, Thursday, and Saturday.
You might ask your coach if he can set aside 1 lane on Tuesday and Thursday for those who want to swim the other strokes. You might be surprised to find that there may be others who would like the change of pace. Then if there is more interest you might get him to give 2 lanes, etc.