Accrued HVC points are basically worthless. I have been a Welk owner, now HVC, since 2010. For years, I watched all availability disappear precisely 60 days before arrival date. Want to book a May 1st arrival? Availability will disappear on March 2nd.
We moved up to Platinum Priority IV in 2018, and suddenly the "60 Day Disappeance" vanished. As a Priority IV owner, our accrued points have a 120 day booking window, and we are able to find availability pretty much anytime in that four month period. We concluded that at 60 days prior to arrival, all availability must either transfer to nightly rentals or be limited to Priority owners.
As for depositing accrued points into II, that is allowed. I don't believe that II puts any restrictions on those points. Someone else may know more about that than I do.