I have 3 lab sections and I am wondering if there is a more efficient way of posting assignments across the 3 labs w/o having to enter them individually to each section.
As individual courses like you currently have them, no there is not a way. Something to consider though is to cross-list your courses into a single Canvas course site with all 3 sections in it. This will make it so that you only need to add and maintain content in one place instead of three. You'll still be able to set different due dates by section, view the grades just one section at a time, and communicate with single sections or combined as you like.
BUT....... If you already have much student data in the system this semester it might not be a good idea to cross-list right now. Student data such as grades and assignment submissions will not move if you cross-list a course. So typically it is something I only suggest people do BEFORE the semester starts, or very early in the semester if there have not been any assignments yet. Keep that in mind before using the information in links I'm going to provide below.
How do I cross-list a section in a course as an instructor?
How do I de-cross-list a section in a course as an instructor? (in case you change your mind)
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