Yes, you absolutely can and should stock forage in the spring.
My own, somewhat cynical opinion is that some (NOT ALL) suppliers like to push HBG because they can charge more initially and will get you as a repeat customer because these fish will need to be eradicated, then restocked in the future.
I'm personally a strong proponent of true bluegill as a forage for creating good, balanced LMB fisheries, even in small ponds. Feeding can further enhance the bluegill population and create more, healthier YOY bluegill each year for bass to feast on, but once again water quality is paramount if you are going to heat up the food chain with a few pellets.
