Ask HN: Different investors on a GPL project, and conflict in IP?

I have a product licensed AGPL. It's hosted on Github and everyone can install and use it without me. I also provide commercial service for this product and provide extra features, enterprise support for maintenance. One of my customers is an enterprise e-commerce company, they build some e-commerce softwares for a couple of big enterprise retail companies. They offered me a deal: we will fork the man product, change its name and their developers will develop extra features for e-commerce websites.

They will continue to pay me for the extra services that I'm already providing and the new product will be brand new product which is not related it the current one as the claim because we will fork the repository and all the releases and development cycle will be different for this new product. I will take some money for my consultancy and also the relationship will be based on profit partnership, I will take commission for each sale and if I don't allow them to sale the product to a specific customer, they won't be allowed to sell it.

The main problem is that the new product that they're willing to develop won't be open-source, which violates the main rule of GPL. Therefore I need to license the current product just for them in order to be able to work with them.

Our company is also in the process of getting angel investment and I'm wondering if this deal can make some trouble to me later on. If I share my company's IP with another company, I guess the investors won't like it and the valuation of my company will decrease.

On the other hand, my product will be used my many enterprise companies which I can't actually sell myself so it will be widely used and proven software even if the name of other product will be different.

What do you think about my situation? Would the investors really decrease the valuation in this case? What can I do for the licensing of my app in order to avoid any legal issue in the future?