Any time you use something other than a hard mount for the plate, you introduce variance, not just one keyboard to another but even across an individual keyboard.
Take a switch that feels great in a wet noodle and it will only feel the same in another equally wet noodle.
Find a switch that feels good in a stiff board and you can swap that switch into any other relatively stiff keyboard and it will feel (pretty much) the same.
Stiff is easy to replicate, a wet noodle is not.
If you want a specif feel and translate it from one board to another, you're going to have to get onto something stiff and find what works for you. This goes double, or even triple if you plan on ever switching to an aluminum case where stiff is pretty much the norm and people try to replicate a soft feel out of a hard material (which is difficult).
This doesn't mean you have to give up a softer feel, you just need to build it into your switch choice, NOT the chassis. To give an example, here's a few of mine..
The Filco - THICK beefy aluminum case, oversize stainless plate, sandwich style mount, Jailhouse Cherry MX blues with soft springs, super crisp typing feel but only slightly more harsh than an old model M or my GMMK with Box Jades. It's darn near perfection really.
My Chinese custom - solid aluminum, aluminum plate, sandwich style with J-spaced Gateron Blues, this is the least harsh board I have ever used. It's on par with my plate-less 75% Vortex Race with plastic case/MX Blues. This board is best described as mushy. I haven't really used it because of it, a shame since it's really nice.
Then we have the Nk65 - a thick aluminum case but with a hanging top mount aluminum plate and dampened Zeal Zilent V2 switches equipped with super ultra light springs. In theory it should be one of, if not the the softest of my aluminum keyboards and yet this is by far the most harsh keyboard I've ever used in my life despite all of the things that should help. The tactility on the already extremely tactile switch was amplified 400% with my spring choice and when the switch crests the activation point it causes a crash to bottom and the small amount of dampening by the switch is just not enough to counter it. The typing experience is best described as typing on a cloud, hitting a brick wall (tactile bump) then falling off a cliff onto concrete. It's ROUGH to say the least.
On most switches swapping to softer springs softens the tactile bump along with the ramp, so on MX browns you have a 35gram(g) ramp then a 5g bump (40g actuation), then it eventually ramps up to 60+grams at bottom out (spring rating). On these, due to the housing design, the tactile bump remained at the normal 45g or so but lowered the ramp up to it and following. So instead of a 35g ramp these now have a 15-20g ramp up to a 45g bump, meaning the bump went from 5-7 grams to 20-25g. It's less a tactile bump and more of a tactile wall. Fun, but not for everyone.
Switches will make or break the best or worst keyboard and adding case design/flex to the mix only makes it more difficult to weed out the problem.
