I did my 4x4 transmission working from a pit, it was a bit too heavy and cumbersome to have done on my back using axle stands, doable when I was younger and more stupid but you would need more height than standard axles stands would give.
I would have no hesitation doing a 2wd VAG transmission on the drive, there are some very good youtube videos of a guy who does mobile clutches doing them on his back on customers driveways, he doesn't even use an engine support bar but he knows exactly what he is doing, what to support and where.
I bought an engine support frame and having used it would consider it essential, it wil also serve as a support for ratchet straps to take the strain of lowering the gearbox if you have someone to help you who can be above to manipulate them, the gearbox is rather unbalanced and really needs a transmission jack attached with chains, not possible on a driveway and you will see the guy initially lower the gearbox on the trolley jack before rolling it onto his chest and down to the ground, you dont want to be doing that with the 68kg weight of a 4x4 6 speed transmission.
Because of the weight, that there wasn't really room for two of us in the pit (one should always be above in case of emergency) and the danger of the transmission falling 1.5m (we didn't have a transmission jack) or simply me trying to pass out a 68kg weight above my head or lower it to the bottom of a confined pit we chose to put a platform across the pit, jack the vehicle up so as to lower the transmission onto the platform and slide it out, so effectively it was removed in the same way as on a driveway using the same trolley jack and axle stands, I did have the advantage of standing upright though rather than lying on my back.
Both of us were over 60, at 30 I would have done it unaided.