As SHC, it's difficult to estimate due to plot determining power. With such, there's also a lot of things to take into account, such as if he'd only stick to training solo at Mount Paozu or if he'd go into the Rosat again. The latter's the only way I could see him surpassing his Z-Sword self, given the hype that the training received. Training by himself in the mountains logically wouldn't provide a greater boost than Vegeta's gravity training either, unless you have Gohan's potential being a huge factor.
At the bare minimum, I'd see it being like the difference between his Ultimate self and Base GT self, so not a huge increase. At the absolute best, stronger than his Z-Sword self, depending on what his training regime consists of.