That's why I said 'natural feedback' and specified the direct out... there are feedback/hold effects on some processors, there are pedals like the 'freqout', magnetic devices like sustainers, etc. On a device as flexible as the Axe you can create a loop in your signal flow to simulate/create feedback like effects but it is not going to interact with your instrument like actual feedback, because its not interacting with it beyond manipulating the original input.
I think I have messed with a feedback simulator preset using the Exp pedal before on the Axe. IIRC the entire preset was built around getting that to happen and still was basically a novelty for my use. Certainly fun to mess with but ultimately not something I would consider a genuine capability of the device... Might be useful as a special effect or substitute for the real deal if it was really critical to what you were doing but just like the fuzzes, it's a compromise and all you need is a power amp and cab to get the real thing.
You can create 'fuzz' on a modeler it just doesn't work the same way as an analog device. Shrug. You can compromise on it, so you can do everything in the one box or you can supplement your gear. Some people might even prefer it with a buffer. I have been wireless for a long time, so I don't care... there would be a buffer in my rig even if it was all analog.
There is just a really good reason its not likely to be any more authentic vs guitar->cable->pedal than it is currently.
@Elric i have a ton of awesome fuzz pedals and actually love boosting them with a boss hm2 and often use fuzz in the loops of my boss ls2 line splitter so i dont know whats up but it typically still sounds great to me lol