Xue Sheng
All weight is underside
I do not train aikido and I am basing this on my background in Taiji Tuishou so I could be way off the mark, but it would seem to me that a person learning to be a good uke would be equally advantageous in a real world application as it would be to be good at Aikido. If you are not movable it is as likely to throw the other guy off and give you the advantage IMO.
However there would also be a disadvantage to being to rooted which I would think if one learns to be a good uke they would figure that out as well. And of course learning how not to be afraid of the fall, or attack, in the dojo would also be advantageous outside when you are in harms way.
IMO you are just cheating yourself and your training partner if you help them execute the technique by jumping or making it easy
However there would also be a disadvantage to being to rooted which I would think if one learns to be a good uke they would figure that out as well. And of course learning how not to be afraid of the fall, or attack, in the dojo would also be advantageous outside when you are in harms way.
IMO you are just cheating yourself and your training partner if you help them execute the technique by jumping or making it easy