I can see neither one of you are framers

I used mine daily when I was.
I'm not a professional carpenter. I've never even had the chance to play one on TV. But, I've framed a few houses over the years and and have built a number of barns and out-buildings. I've been living in this house since the early 1980's. It was a "pay as you go" project that I cleared, leveled, formed, poured, framed, roofed, trimmed, plumbed, and wired. I had a friend do the sheetrock and another do the floors. It survived the eyewall of Katrina and a decent sized pin oak falling on it so I guess I got it kinda close to right.
I built my first tweakers out of scrap lumber and carriage head bolts as needed. For floor joists, a three foot handle was nice. Later, I advanced to angle/flatbar/water pipe, etc. A friend lost my last revision one a while back and replaced it with a store bought one. It's a no name copy that looks like the Mayhew. It really makes the "shark fin" gadget like comparing a bumper jack to a twin post rack.
There are a lot designs out there by a number of companies that are far more clever than the Mayhew design though. Some are even adjustable. If I was making a living doing that type of work today, I'd probably have a couple of different designs of them to try and cover a few extra applications. I'm going to have to stand by my original idea of using a bench grinder to defang that hammer though. I can easily forsee that that fin will end up drawing blood of the user.
Google "lumber tweaker" and then hit "images".
Adding that "shark fin" to the hammer is like putting a built-in can and bottle opener on your favorite beer mug or your framing hammer. Will it work, hell yeah! Is it a good idea, or really needed? Now, be honest...........
WoD