I have never used mozaik or any other cabinet software but I can tell you that there are a surprising number of details in designing a cabinet. It can be a are a real pain in the behind. Many many decisions and you will have many re-designs as you find out where you made mistakes. For a complete kitchen, I would think that it would be worthwhile to go with a commercial product.
I can say without a doubt that it took waaayyyy longer to build the cabinet with CNC vs doing it the old fashioned way. I started building cabinets for my wood shop with traditional tools but found that I was not good enough to produce a product as accurately as I wanted it to be so I went the CNC route. It also was a good way to justify a new tool/toy.
There are a lot of things to learn so even with commercial software you will find that nothing beats experience.
Plan on making many mistakes unless you are well versed in the art of cabinet building. It is NOT a case of slapping down a piece of plywood (btw, how are you planning to hold down the stock?), loading the pre designed cabinet layout, pressing the button and magically you have all the parts for a cabinet. If you work full time, there is (IMHO) zero chance of getting an entire kitchen done in the three month paid trial period for mozaik unless you have an extensive history in building cabinets and an equal level of experience running a CNC router.
Also, don’t forget that cutting the bits and pieces needed for a kitchen is only one aspect of the build.
To sum it up, if you just want to save money on your replacement kitchen, this is not the solution. It will also not going to be fast. If you are into wood working and want to expand your horizons in that endeavour than by all means, go for it. Just don’t think that the CNC will magically turn you into a custom kitchen builder overnight.
Another aspect to consider: Does the mozaik software have any optimization for people that do not have a commercial level of equipment. If you do not have a tool changer but the software was built with a tool changer in mind (ie equipment any commercial shop would have), you will probably be really surprised at the amount of time wasted changing tools. Again, I have never used software such as mozaik so I really can’t say if this is something one should be concerned about.