Hi Klassen and welcome to a very informative and friendly forum. I am a newbie as well, but the knowledge and insight offered by everyone has made planning our trips a lot of fun. I don't know any other way, except to log in to the Virgin website each day, check the search for our identical flights, and select the "points" tab instead of currency. If you get 4-5 columns dropping down, then there are Reward Seats available, sometime PE and sometimes Business - sometimes both! The further ahead you plan, the greater chance of them popping up. We booked our PE seats in January, the following week those flights had reward seats, but husband was only Silver Status, so we couldn't upgrade long haul.
Another way is to go into "my bookings", select your flight, then click on the "upgrade" options - if there is reward seat availability, you can upgrade online, or go on the waitlist. Remember, you are looking at around 180,000 points to upgrade one way. (45,00 per pax per sector).
Hope it works out for you. Glad to hear others are having success, maybe it will happen for us too