If you'd like to test standard track versus adult, there's nothing stopping you. Even though you've passed APB and freeskate, the requirements are slightly different for Pre-preliminary (I know USFS just added spirals to APB MITF, so less different now) so you can start from square one.
But, I'm curious: if you're only competing against yourself, why do you object to the competition/program requirements for adults? What difference would it make if you tested standard track?
Interestingly, your objections echo what I hear about ISI tests and competitions (or at least before ISI introduced the open categories).