Sidemount doesn't really lend itself well to standards.
Not currently, but eventually the range of gear configurations will settle down to 1-2 main approaches and 1-2 "alternative" approaches. It's what happens with every new activity, from autos to mountain bikes to scuba. Then standards will emerge.
At the start of a new activity there are endless things tried. That's a good thing, but after a while what works best, what is most economical to produce, what is easiest to teach, what is most durable etc. becomes apparent and the field narrows. That's not a bad thing either. Look at the evolution of suspension MTB's 15 -20 years ago there were many many ideas being tested, most are a memory.
What happens on the marketing side is also predictable. The offerings become more similar and we find the various brands screaming ever more loudly about smaller and smaller differences. Look at the big beer brands, they have been reduced to marketing the container (temperature indicating bottles and wide pour mouths etc.) because the contents is basically all the same.
We are early in the SM "revolution" but give it a few more years and there will be fewer choices and more standards. It's what happens.
Of course this alone will sour some who were attracted to SM by a need to different. Once something becomes "standard" and main stream there is no status to had by being a "bleeding edge innovator". This stage often kills the growth as the "need to be different" crowd frequently spends freely.
The folks that migrated to SM (or suspension bikes or whatever ) to fill an operational requirement usually stick around as they weren't motivated by status seeking.
This is just the natural "life cycle" of the new and different.
Tobin