TIme is a precious commodity and one you seemingly have less of each day as you approach the admissions cycle and your senior year in High School. As others have mentioned, you have maxed out WCS points for the activity with the achievement of Eagle Scout. Additional pinnacle achievements like Venture Summit or Sea Scout Quartermaster are of great resume value, but questionable admissions point value because the assumption is that there is one check box for admissions to mark complete - Eagle/Gold (or equivalent).
Leadership roles are always great IF YOU CAN DEMONSTRATE IMPACT. Holding a role is different than being a leader. As others have suggested, if you can anchor into a role that allows you to document your impact, that is always beneficial to you as a person but also in your quest for SA admissions.
There are two paths forward - resume building or simply having fun to enjoy the time you have left in High School. Under ideal conditions, the two paths are aligned and you can do both. In my case, they were different (but I still had fun). After earning the rank of Eagle, I served as JASM for my troop (after previously serving as SPL and OA Chapter Chief). I used the opportunity to shift time commitment away from BSA and into CAP. I rose through the ranks of that program and assumed the role of Squadron Commander during my senior year. In a way, it let me max out one program and then pivot into another that allowed for additional point scoring with new available check boxes on the admissions form.
There are many ways to approach this quest, and there is no singular path to success. Someone may work to achieve as many activity check boxes as possible (i.e. Eagle, Boys State, Class President, Varsity athlete, Team Captain...) and then there will be the other successful applicant who tripled down on one activity and demonstrated major impact. The vast majority of grads and parents here would advise to pick the path that interests you the most and roll the dice on admissions. Your appointment is not guaranteed and it would be unfortunate for you to have tried to game the system or follow an ill-defined recipe that did not result in success.
Hindsight and regret stink. By going with your gut and following your passions, you will do your best work and the resume should speak for itself when you are done. In my case, I received the appointment and that was the ultimate goal. I enjoyed my time in High School, but there was a focused mission to achieve as many points as possible because I knew my superpower was not academics or athletics and I needed all the EC points I could garner to elevate the admissions package. Does achieving Eagle complete your personal goals and objectives for your time as a youth in BSA, or are there higher level roles at the district, council, section, or national levels that would be of interest to you? Starting a new activity can be exciting, but you do have an opportunity to springboard your experience and knowledge into serving a larger audience within a program that you are comfortable with. Only you know the answer to this.