Engineers Squares tend to hold square, traditional try squares can easily go out of square. Tbh, it's not hard to resquare them.
@Joshua Slocum is right though, most chippies today buy hardpoint saws and don't sharpen. Figuring time saved is money saved, but you still need to factor in the time to get in tge van and go buy one. Resharpening saws is a doddle though, takes 10 minutes.
You need two saws though, a rip and a crosscut, rip is sharpened at 90 degrees to the plate, crosscuts around 60ish. Most hardpoints are crosscut hybrids so not really great for ripping.
I was in a nursing facility the entire month of May following surgery. Pain meds were available upon request . . . and I did. What they didn't do was warn me of the side effects . . . passing cement blocks!!!