Drive chain swap clarifications

First, it seems as your goal is for a higher ratio on the top end of your gearing so that you won't as easily "spin out"--require such a high RPM to maintain or gain bicycle velocity that it's physically impossible to maintain or achieve such a high RPM. The fact that you are using a 30 tooth chainring infers that you are on a mountain bike. That it has a QR 10x135mm rear hub infers it is an older mountain bike or some form of hybrid bike. In either case--and for many other compatibility and cost reasons--moving to a 12 speed cassette that may have a 9 tooth high gear sprocket to achieve that higher ratio will not work because a 135mm spaced hub has no room for over 11 cogs. As you realize, you require a MicroSpline free hub for 12 speed Shimano cogs and your current hub is not likely to be compatible for one. There's no point in researching that due to the incompatible spacing to begin with. Note, as well, that going to an 11 or 12 speed rear will require a new shifter and rear derailleur since a 10 speed shifter has only enough detents (9) for 10 cogs and a 10 speed derailleur is not directly compatible with 11 and certainly 12 speed systems. There is quite a bit of expense there, even if you had a compatible hub and frame spacing, when a bigger chainring will achieve the goal as well.

The easiest--really the only-- way to get a larger, faster top end gearing ratio is to simply replace your current 30 tooth chainring with a 34 or 36 ring. Thirty-two tooth ring won't achieve much gain in your high ratio. Probably wouldn't even be noticable.

Hyperglide is the freehub format that Shimano used for its 9 through 11 speed mountain bike and road hubs. However, when Shimano launched its 12s MTB, 1x drivetrains had become almost universal on MTBs, and they may work best with 10t cogs. The Hyperglide freehub body has too large a diameter to accommodate a 10t or smaller cog. Thus, Shimano went to Microspline; that freehub body is truncated at the end, a bit like SRAM's XD and XDR bodies or Campagnolo's N13 freehub body.

Some third party 12s cassettes can fit to Hyperglide freehubs. These can only accommodate an 11t small cog.

In principle, Shimano might be able to design a microspline freehub for that particular hub. However, it might not be economical for them to do so if demand is too low, or it might be impractical due to the dimensions of the hub. The hubs on many higher end wheels have had microspline freehubs released, but again, not enough commuters might want to pay extra for microspline hubs. It's also worth considering that it's often cheaper to just sell the bike and get a new one with the desired spec.