Is there any IP in kendo?
So many answers. If you read all the posts about IP/aiki, you find that it isn't a simple matter of "Is there any IP in ...".
Liu Chengde, Chin, Akazawa, Okamoto, Shirata, etc, all had to learn it from somewhere. More important questions should be:
1. Who has IP/aiki?
1a. To what degree?
2. Can they teach it?
2a. Do their students have it in progressive levels?
How to judge answers?
1. He/She must absolutely, without question, stand out from all other martial artists. And also do so outside of any technique or waza. High ranking kendo people could not understand how Ueshiba was doing things.
1a. Train with a wide variety of people. Research for known, vetted people. Martial artists went to Ueshiba because he was well known and vetted as having extraordinary skills.
2. Train with them. If you haven't started standing out in 3-5 years, the answer is no.
2a. This also will give you the answer to 2. Not amount of knowledge of techniques or kata, but unusual abilities/power/strength within waza and more importantly outside of it.
Finally when looking, IP/aiki should be able to be used in any martial art because it changes the body, not amasses techniques. As Ueshiba said, paraphrasing, Aiki makes everything better.