There are books all about assembling transcripts for homeschoolers.
Cafi Cohen has written several on homeschooling teens and creating homebrewed transcripts. One of her kids was accepted at multiple service academies, and ended up going to the Air Force academy. He'd done a lot with the Civil Air Patrol and a personal fitness program, as well as the usual academic courses.

I spoke to a Yale admissions officer a few months ago, in preparation for a talk I was giving. He said that they were very happy with the way homeschoolers fit in there, and that a higher percentage of homeschoolers were admitted than traditional students. He was very enthusiastic about what homeschoolers could bring to thee table, though he did say that the expectation is that they will have made good use of their freedom to pursue out of the box endeavors.

My kids have done some work with mentors, and I really can't say enough for caring adults who take time to share their expertise. Mentoring is one way for kids to go deep into a subject, without a lot of cost and the awkwardness of being 8 or 10 years younger than most other students in a college classroom. Artemis had an email relationship with an entomologist when she was about five. Hector has worked with two different geologists and now has a math mentor.

I just read a report that talked about ACT and SAT correlations with college readiness, and apparently my son would have been ready several years ago, according to the charts. But I don't think he would have enjoyed the experience at eight, and I am not convinced that his intellectual capacity should ever overrule his social and emotional needs. I think we've done the right thing by him, by waiting, and he's growing into a confident and well adjusted young man. Perhaps he could have succeeded in college at eight, but FOR HIM, it looks like twelve is going to be the right time to start. And it will certainly not be full time...