I can edge glue boards without all that and they are plenty strong . A little more effort to align them I suppose, but otherwise I don't see the point. If I did a dowel jig is trivial to make.
Thank you! Youtube has been trying for ages to get me to watch some clickbait video where the thumbnail is a nail between two pieces of wood. Now I finally know what that does without watching the video.
And if you tape it into the corner of your combination square:
the rule part of the square keeps the reference faces aligned vertically
the nail can't tip toward one board, causing vertical misalignment
consistent centering (or off-centering, if that's what you want)
I find it's easier to position the rule on my layout markings than to position a handheld nail. There is a slight offset, of course, but if that's a consideration, do your layout to compensate.
I find it's quicker, too.
If you are doing floating tenons, just mark the ends. If your tenons need to be vertical with respect to your reference face, use a long nail or screw, mark the tops, adjust the height, mark the bottoms.
If you can tolerate more offset or are willing to always layout to compensate, drive a woodscrew vertically in a long narrow block with only 2 square faces. Adjust the screw depth as appropriate. The block gives you something to hang onto without taping anything.
And now I bet you're envisioning the construction of your own dedicated jigs made from scraps and wood or drywall screws.
I absolutely agree, usually I go for the ganged up edge planing to get that complementary mating edge. Also if I were more than a hobby shop and doing things for money on a time budget, I'd probably think about buying some of that oh so expensive Festool stuff.