Im thinking more in line with a hydraulic grapple style. Think danser intimidator.
I have a danuser intimidator. It works well (within the limits of what my tractor can do), but it's heavy - and depending on the rear ballast used (e.g. finish mowers or other implement that hangs far off the back of the tractor) can cause the tractor to start rocking fore-aft like a teeter-totter after hitting a bump (or operator-induced oscillations fore-aft). Which likely indicates it's probably at the heavy end of what I should be using with my loader (if at all).
Best technique I've found is what I read (somewhere) where you approach the post/tree/etc. grab it, lift slightly (just enough to load the front wheels) and drive either forward or back to loosen the post/tree, before lifting fully. ..... basically the same technique as removing posts/trees by hand (rock it a bit, and then lift it out). The thing to watch for is to make sure the tree/post is close to centered before closing on it as otherwise the closing of the jaws will put a sideload on the tractor's loader arms. I've managed to avoid doing damage so far, but make a conscious effort to center the object before grabbing it.
Have been tempted to try putting it on an adapter on the 3-pt hitch and see how well (or not) it works there, but haven't gotten around to it yet.
Overall, it's a handy tool as a grapple/post puller, but that specific implement likely needs something more than a compact tractor to fully leverage the implement's capabilities (using it as a stump bucket on a compact tractor generally hasn't worked that well). .... having said that if I had to do it over I'd still buy it given my uses and future plans (which will likely/hopefully include a larger machine at some point).
So proper ballast (heavy and preferably not hanging far off the back of the tractor), and grabbing as close to the ground as possible is definitely advisable as are the other suggestions/guidance that's been provided so far ....
...just my :2cents: ...(which is hopefully coherent as I'm still in the process of waking up)