Does anyone have experience requesting IP Releases from pre-startup research partners? Looking for something along the lines of: "The company is being created, you don't want to be a part of it, so you are releasing all future claims on the IP."

Have an IP attorney draft an Assignment document up for you. Working with an attorney is helpful especially if you can't get ahold of some of the parties you are trying to get signatures from. Most contractor/consulting agreements have these types of statements saying that all IP created is owned by the company and the contractor or consultant has no rights to it.
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