I basically have the same statistical backstory as you. I graduated in 2015 with a 2.7 cGPA and a 2.38 sGPA and then did a 2.5 year postbac until I got both of my GPA’s above 3.0. I ended up getting a 507 on my MCAT, which was disappointing at the time but still higher than the average for my state school who I received some love from and am currently waitlisted there. If I don’t get in, then I will reapply this year ED and I have confidence that I will receive an acceptance next cycle (God willing).
I’m telling you all of this because as long as your extracurriculars are solid and you do well on the MCAT (relative to UCR’s standards) then I think you should try applying there for one cycle before doing an SMP. It may save you tens of thousands of dollars and a couple of years of time.