You need the jib to help tack the boat. There are few things you can do to de-power the boat. Use the main sheet traveler more by traveling out it move the main out and spills more wind. Then when you get ready to tack bring the traveler in to harden up the main some to get your speed up to tack. Also you can put your jib blocks on adjusters to open up the slot more between the main and jib. I have put a jib furling system on my G-Cat 5.7 which reduces the jib area because I added a spinnaker. If you need help with any of it let me know. It takes a lot to stuff the bows of the G-cat because as the boat picks up speed the deep V symmetrical hulls generate lift. But if you really push it and try hard enough you can stuff the bows but I’ve never pitch poled just cartwheeled. The G-cat 5.7 has one of nicest rides of any beach cat but they will flip sideways. Also "cowboy" the main sheet with several wraps around your hand and you can drop a loop. I usually do not sail in gusty winds with the main sheeted in.