I have a Ball canning book which I used to try to determine how long to cook them. The book that came with the canner I misplaced. I found a soup recipe which had tomatoes, onions, and other vegetables which said 55 min. Some of the other recipes included some kind of bean and had longer cooking times. I figured the longer time was because of the beans. So I added 5 min. to the soup recipe, which had the closest matching vegetables. I’ll have to try one of the jars, but just looking at them, they look well done. I was afraid to go less. Part of the problem is that most recipes that have squash have it pickled. I didn’t think that was the same as just canning. Maybe I’m wrong.
Overtime is the better part of valor- taking the vegetable that requires the longest time is the rule of thumb. You are ahead of me, I have never seen recipes for pickled squash.
More power to you for doing the canning.