One strategically valuable area of collaboration is naval development.
Ironically, this is the one "big" area the U.S. seems to like seeing us develop and India doesn't care about.
Namely, no matter what the PN does at this point will affect the capability of the IN. The IN is ahead in the surface and aviation domains, and will likely remain so. Even if the PN reaches its ideal state, the most the IN loses is its ability to impose a MEZ in the Arabian Sea. However, India can live with that because it can still maintain its trade links to the Gulf in contested waters.
Thus far, the U.S. hasn't stopped the PN from securing ITAR-grade inputs for the Babur-class corvette or Sea Sultan LRMPA.
On America's part, there seems to be an intentional willingness to let the PN develop. Short of literally building a fleet as large as India's, there's nothing the PN could do in its build-up that'd strategically threaten India. The only potential thing was the specter of an SSN or SSBN, but that won't happen due to various factors (e.g., iron brother now stainless steel brother, Daku Dar and Maryam Nawaz Senpai).
So, I can see the PN potentially stepping up its collaboration with the South Korean industry, esp. for critical inputs for future NRDI-designed ships. Heck, the PN might even pursue ROK-designed conventional submarines. Basically, the 'worst' that can happen for India is that the PN builds a really good A2/AD setup, but that in itself doesn't threaten India.
tbh, I actually wonder if the U.S. would go ahead and release the AH-1Zs if they went to the PN/Marines and, in turn, used for elaborate peacekeeping or U.S.-led coalition purposes.