Its known whether being a perfect jinchrucki restricts the ability to suppress the fox. Im starting to think it does. Madara's or should i say the ms ability to control or suppress the fox's chakra is limited to the fox either being on the outside or inside an imperfect jinchrucki and thats why i believe mito sealed it in herself because then madara will have no way of controlling the fox. Mito had been hinted to have great control over the fox and the reason i say this is because tobi commented that km naruto has the same ability as mito, the ability to sense evil intentions, an ability which comes from being able to control the beast in you. If the reason for mito sealing the beast in herself to take over madara's arsenal, then its possible that a jinchrucki who is either perfect or has control over their beast is also outside the range having its beasts powers suppressed or controlled