Can Ultra Instinct be used on top of other transformations, like Super Saiyan Blue Ultra Instinct? Ultra Instinct is sometimes refered as a transformation and sometimes as a technique/state. Now apparently there are thousands of fans who believes Ultra Instinct can be used on top of another transformation, just like kaioken can be used on top of Super Saiyan Blue and make Super Saiyan Blue kaioken, they believe you can have a Super Saiyan Blue Ultra Instinct or a Super Saiyan God Ultra Instinct. 

Personally I dont believe this is possible, but there are thousands who thinks so and this situation already has consequences in the Dragon Ball fandom, for example there is a videogame mod of Dragon Ball Xenoverse which allows you to use "Goku Ultra Instinct Super Saiyan Blue Kaioken"

http://www.youtube.com/watch?v=lXHuC2d-0-c&amp;t=9m18s



and there are also fan arts made about it like this one,

https://i.ytimg.com/vi/FBGPK6OZsZU/maxresdefault.jpg 

Are all these people just wrong or is there any hint/explanation in Dragon Ball Super that states this is possible?
This is an interesting question, however, as of now I think the answer would be a no, with regard to stacking it up on top of SSJBIn the anime, The UI transformation was indicated to be a massive power multiplier, even a lot stronger than SSJB+Kaioken*20, which is a reason why we see Goku being able to block Jiren's hits despite his god of destruction like power and also overpower high tier characters like toppo without any effort. Also, despite the Self movement ability being a skill, we see Goku undergoing a transformation and he doesn't utilise it naturally like Whis or the other angels. However, it is possible to stack kaioken on top of it as kaioken is a special technique and not really a transformation. Hence goku would be able to utilise Kaioken with the UI transformation assuming his body is capable of handling it.Now  there is a possibility Goku might be able to adapt this transformation into his base form where he is capable of utilising his self-movement ability without undergoing the transformation. Maybe something like the SSJ transformation during the cell arc, where Goku mastered it and managed to stay in it for a prolonged period of time as though he was in his natural stage. Also this can also refer to him absorbing the god form into his base form or him utilising god ki in his base form.Although, this doesn't seem practical as the UI transformation multiplier seems to be significantly higher than SSJB based on Goku's fight with Jiren so I don't see why goku would wan't to stack the skill with SSJB. Maybe utilising kaioken with the UI transformation might increase his power humongously.