What features would you like to see in Pixelmator Pro?
I would really want to know why I cannot start a line on another line or shape but for some reason I can't. Is this a design choice or just a bug. For now I can work around this issue but I already know that it will really annoy me sometime. I didn't have this problem when I used the old Pixelmator.
Understand the annoyance. For now each line or shape you draw will be added on a separate layer. However, you can merge those layers by using the unite function in the draw tool, freeform tool or shape tool options. Then you select the separate shape layers and with the shift key and unite them to one shape group with the unite option.