I've been pleased with my machine so far. I do have the issue where it stutters a bit after the advance kicks off at 20 minutes, I've not made an appointment to have the advance adjusted yet. Other than that and a weird hydraulic leak they took care of the first week, it has been flawless at everything I've needed to do.
I figured the chain in the hooks as they are, routed over the buckets, with the buckets as they are in the above images would give me the best max height. The top edge of the front bucket rolled forward (dump position) isn't quite as high as the front edge is with it rolled back, not to mention the fact if you start with the bucket rolled forward to dump, chain to what you want to grab, you can lift and roll back letting the chain wrap around the bucket and get over an extra foot of lift over what the loader itself reaches.
I agree chaining off the back of the bucket could hold a load in closer allowing for heavier lifts, but most times I want things out far enough they'll not hit the tractor. If I did one backwards, I'd be doing so to get the maximum weight lifting capabilities of the tractor. As was mentioned, the metal around the welds would be what would likely fail if anything, so trying to get the maximum weight the tractor can lift out of the tiny area the hooks connect to wasn't my goal. The steel on the top edge of that loader bucket is pretty darned thick, especially compared to some others I've seen, but I don't see me going after anything more than 1000# off any of those hooks. The hoe bucket I don't think will ever fail around the welds, it is a good 3/8" thick plate the hook is welded to. If I was to add one for maximum weight I would probably weld a hefty full-width flat bar inside the top of the bucket and center the "backwards" hook. Even fully ballasted with rimguard and backhoe I've lifted the rear end with the front loader on heavy lifts.