Regarding the frequency of this wax' application, I dont think it would harm if you layer it every few months... Layering it with itself more frequently may cause streaking (and even slightly muting paintwork) but thats primarily applicable to the collinite waxes only. Almost all other waxes tend to work fine when layering them frequently.
Regarding the habit of routine waxing, this wax serves a different market mostly of consumers that aren't either regular with waxing their cars, or take them regularly to a service station for wash (which is a norm internationally) and importantly provide a season long durability (considering the extreme snow/rainy weathers into consideration when its impossible to do anything to your car even if you're a detailer and I have witnessed this first hand). Keep in mind this is an old timer several decades old wax but still has its strong hold.
Having said that, quite a lot of detailers like to have collinite 476s and 845 as their base protection and then top it with beauty/luxury waxes frequently.
Yes, it went out quick. Several people reached out after that.
For you, it will be expensive to get this wax all alone via airmail as shipping + customs would get into play. I wouldn't suggest spending so much on this alone. If you have someone in china, i could recommend another solid durable super wax that lasts as long as this. When someone is travelling though from UK, you could get this ordered and feel free to reach out to me for advices on the minimum set value for money products you can get and I'd be happy to help.