SEO promotion - intellectual property?

Question

Search Engine Optimization

Hello everyone,
it became necessary to transfer the promotion of your own project to the wrong hands. I no longer have enough time, and the SEO specialist from me is so-so. However, I am a very good web programmer. At least that's what everyone with whom I've worked and still work with and where I've worked thinks so.
Knowing the internal structure of web studios, I am very afraid to transfer the project into the hands of a school SEO specialist or a pseudo-studio, so I choose a studio very carefully. I found one that seems to inspire confidence: clients are really advanced, sites work, my own site is not buggy, etc.
I talked with their manager and in principle everything is cool, but I caught one moment. They claim that the results of SEO promotion are their intellectual property and in case of termination of the contract they "take everything back".
A couple of questions arise:
1. How can I take back the promotion? (Without buying links, I note)
2. Is this generally a normal practice?
Location - Krasnodar. Of course, I will not name the studio.

Answer 1

Yes, there is such practice. Year in 2007 was everywhere. It is still widespread in the regions. And no, it's not normal. In addition to links, texts can be taken away, for example, the structure, titles, etc. can be returned back.
It is necessary to keep the client by the result, not by threats.