What does permakin mean? Kintypes are always permanent. If they leave then they aren't kintypes. They might be cameos, synpaths or heart types instead. Or do you mean that you are at least somewhat permanently shifted into that type? You certainly can have more than one kin type at the same time. If you have more than one type, you will always be "kinning" them all at once because one does not go away when others exist. (Kin is not an action verb. It's a state of being. It's not something that you do. It is something that you are.)
I assume that what you are asking is if it's possible to feel shifts from more than one kintype at the same time causing them to blend together. The answer to that is yes, it can happen. You are both, so it's not surprising that features of both could appear.
I feel there is some confusion in your wording between having a kintype and having a shift. Kintypes are permanent whether you're currently shifted that way or not, but they never leave completely. You are always you. Shifts can vary in intensity from barely noticeable to dramatic change. Sometimes a person can temporarily shift into something that is not a kintype and that would be called a cameo shift. Not all shifts are kintypes, and lack of a shift doesn't mean that the kintype has gone away.