In the timescale of the next week, I'm only hoping to get a very specific letter from someone at the company that says literally "If the proposal submitted by Dr. [insert the full name of the Principal Investigator] entitled [insert the proposal title] is selected for funding by the NSF, it is my intent to collaborate and/or commit resources as detailed in the Project Description or the Facilities, Equipment or Other Resources section of the proposal." I'm still writing the proposal now (deciding whether to mention Itch by name if I can get a letter, or just "public archive and marketplaces" otherwise). The only resources I actually need from Itch are rough agreement that you are okay with the effort to use your public data and willingness to answer questions about whether I'm breaking stuff -- super minimal. They letter mostly just shows that I've checked in with you folks and that my research plan won't come crumbling down the moment I try to start it up.
Anything beyond that, such as sending one of my graduate students there as an intern to replicate our prototype systems on top of your production stuff, can be saved for far far off in the future.