I’m in the exact same boat, 3500 shards away from a 5th, 43600 points. I’ve come to the conclusion that there’s literally no point trying to get any more as even if I did get a 5th and finished the quest there’s no more meaningful solo milestones until 55/60k which finishing the quest wont get me to those points anyway.
You might as well do this as 30 paragon crystals aren't good odds for getting a 7*. There'll be better rewards for 4th of july anyways for your money than these.