Me and my mate would wait till a new circuit was set and then attempt to send every bloc in one go without rest and time it, we’d then come back the following week and try and beat our time, eventually that circuit would become easy and we’d move onto the harder one and do it again. I think this was responsible for improving my PE a lot.
+1 to what JWI & Jebus have said. The other thing I'd add is, if you can, just to climbing! I was doing the exact same last summer, having always been a boulderer other than a handful of routes in 2020. I certainly did a bit of aerocap work, just sessions of easy climbing 5 on / 3 off, plus 1 min on / 2 mins off foot on campus. However, the main thing I did was go sport climbing at least twice a week throughout the summer! I did lots of volume and generally tried to do things quickly. By the end of the summer the difference was enormous.