Very interesting, Renaud!
Yes, I think she can be converted to junk. Because the Centre of Lateral Resistance is well aft, I think the mainmast will have to move back to station 5, which is the usual place for a Hasler/McLeod schooner, and it will have to carry a mainsail that is a little larger than usual - maybe 70% of the sail area? Both masts would be vertical, and the foremast, carrying 30% of the sail area, would be about where it is now.