The only reason it worked on Madara is that↓
1. He was more worried about his other eye rather that getting cut by Sasuke which doesn't really do anything to him.
2. Madara was still trying to understand Sasuke's new eye techs.
3. His one and only limbo during the time he only had one rinnegan was sealed by Naruto so he couldn't use it to block Sasuke's attack.
Over all, FTG is still superior to Sasuke's S/T as it doesn't have any cooldown and it doesn't slow your reaction time after you teleport.
nice fanfic
1 he couldnt react to sasuke as the latter was too fast for him. being worried about his rinnegan doesnt mean he should get caught in half
2 so? doesnt really change what happend
3 he had his staff, you know the same staff that he used in fodderizing minato. he had it but was unable to use it because of sasukes speed which is much faster than minato.
ftg needs seals and markings to be effective, sasukes s t doesnt. and his s t doesnt slow his reaction time, you just pulled that out of your ass.
OT. sasukes base speed his much better than them. battle wise with no prep, then his s t wins it imo. ftg stil has its own advantages tho.