This is generally a problem with hand grinders and leads to uneven grind. One way I have seen other similar grinders resolve it is by having a metal frame at the bottom the helps stop the twist. Yours doesn’t have one so there is probably no easy way to fix this issue.
I have an Oracle at home which is dual boiler and a bambino for the van. Yes there is a difference, is it worth the £1500 extra and the weight and fragility? Probably not. The coffee is great and unless you are really really serious about your coffee, water, puck prep then the difference is so minor there isn’t anything in it.
Would I pay the same amount for a thermoblock as a dual boiler? Nope.