In the dragon ball universe, there are plenty of methods to significantly boost the power level of the user. We have things such as Potara earrings, Saiyan power-ups, etc. But more recently we were introduced to Ultra Instinct. As this is said to be a form attainable by anyone but mostly used by gods (which is even difficult for them to attain) how strong is it actually? Like how much does it power up an individual that uses it?
This question is mainly based on episode 115 where Goku used Ultra Instinct against Kefla as well as against Jiren in an earlier episode. In SSB form Goku was eventually outmatched even with Kaioken activated. We know for a fact that SS forms basically boost power and speed significantly at the cost of stamina and ki over time. Ultra Instinct is a state of the body, making it respond without having to process the thoughts; making the body capable of an instant perfect reflex to anything.
Goku was able to dodge all of Kefla's attacks which seemed like slow motion to him most likely. But he wasn't powered up. Ultra Instinct doesn't provide ki and such it simply is a state of the body making your reflexes perfect with no time delay. So where does the power output come from? How come his punches and such are stronger with Ultra Instinct compared to all his other forms?
As far as I understand each time he was in his none powered up form, his base form. This means his power level is a lot lower than even kaioken in base form. How come he is capable of having such a damage output? Does this mean a design flaw in Ultra Instinct?
What is the actual power of Ultra Instinct apart from making muscle reflexes perfect?