No it's not. Susanoo is ms technique. It takes more chakra to form PS hence user have EMS to stabilize it, however rikudo chakra does the same (Kakashi for example). Although the manga hasn't told definitely that his eye is MS so for whatever reason it could be EMS but I doubt it.
I feel like MS users cannot bring out their true power because it is forcing itself shut hurting user while in use.
EMS releases new power and frees the user of any strain a normal MS had on the user. Kakashi's double mangekyou had no side effects, no strain, and in a sense eternal before it vanished.
I think the common factor here is that Six Paths Chakra makes your MS eternal. Without it the strain on the eyes is great. Kakashi is proof of this as he is the master of passing out from sharingan and Six Paths gave him effortless control over MS as well as powering him up.
Indra must have had Six Paths chakra the same as Kakashi to have enough chakra to make his Mangekyou Eternal and generate a Perfect Susano'o.
But it still stands that the only ones to use PS were thise Uchihas that unlocked EMS and Then gained the ability. Only Kakashi is the exception because of Six Paths which Indra must have himself.