I'm so sorry to hear of your loss.
Your story about your son bearing your grandfather's middle name.... We are the same as you. When my grandfather passed away, my second son was not yet born, so they could not meet. But my second son's name contains one kanji character of my grandfather's name.
It’s nice to be able to honor and pass on the memories of loved ones by using names and kanji characters.
Thank you for your condolences.