Sony mobile have profound history in having beta program for firmware since Z3 era, then X and X performance. However, while other manufacturers are having a beta program bow, Sony don't, instead they release buggy firmwares and force users to test for them, then report. Look at the feedback at retailer's website you will notice how many issues are software related, and how little progress it has made so far. From source code, it seems the Sony's Oreo is identical to Pixels, however Google can fix bugs every week but not Sony.
Therefore, I would like to suggest Sony mobile to relaunch the beta program.
PS: seems the upcoming flagship will be coming in 8.1, hope it will be better.