For the tips on making homemade mayonnaise, I would skip all of what this article says and just use an immersion blender to simplify things. I don't have to wait for my ingredients to come to room temperature and the blending cup it comes with has the measurements etched on the side so I know how much oil I've added. I've never had a problem and it takes about 2 minutes or less this way. Also, rather than using it to toast a grilled sandwich, I'd rather dip my grilled cheese sandwich (grilled with butter) in garlic mayonnaise.
I think this would also be good for a toasted peanut butter and bacon sandwich. I also think it would be good for a toasted peanut butter and tomato sandwich.
Thin coating all around, 30s per side including all around. It gives the crustiest of crusts, caramelized af and utterly delicious, while barely reheating the insides. It's magic.
The mayo tip that comes to mind that is not mentioned is to use Kewpie mayo. It's just better than other mayo I've used (but Duke's is good too). I didn't know until I just looked it up now but it has some MSG (good thing) and uses egg yolks. I picked some up at Costco and I'm fully converted.