Thanks for the feedback, awesome you're getting good use from the tool.
You're right, the customisation of classes is a massive challenge, but possible if you have the resources and budget.
Classes are very complex due to the multilevel nature of the base class and the subclasses within the bases class. To design a generic custom sheet that covers the design of a custom base class as well as custom subclasses for that base class and subclasses for existing base classes is very complex. There is no easy way to do this unfortunately. It is all possible, but it takes significant time and design thought into covering the current (and possible future, e.g. psionics) base and subclasses. When designing the framework of a custom class and subclass, you try to think about making it universal but there are always exceptions to the "general" rule and new rules that make the redesign changes a significant amount of effort.
The first step might be to look at only subclasses for current base classes, but this is also very broad - they generally follow some template deign principles but ideally you need to make this as generic as possible to cover all classes i.e. include every possible progression for each bases class so when a user chooses any base class, the sub class for that base class can be custom designed.
The tool is updated with bug fixes, corrections and new features regularly. Over time and with releases of official content, the need of custom classes and subclasses will be reduced (there have been many requests for the materials from UA to be added, but I'm waiting for the final versions of the draft materials presented in UA to be released as official "play tested" supplements before implementing in the tool). I see having an unlocked version will not help the community as there could be core design changes in the tool that would not be compatible with any changes made by those who have homebrew customization the tool. Each new release of the tool would in theory require any homebrew customization of the tool to be updated which intern requires a massive amount of effort.
I'm all for homebrews, it's great and that's why customization is there in the tool. In my opinion, 5e has been outstanding in providing a significant number of options for players to choose from using the core rules and that's great. Let's see how new features (or stuff that is converted from previous versions of D&D) of the game are implemented (i.e. psionics) and how that will impact the game overall. I think the it's great that the D&D design team are focusing on making fewer but bigger decisions and focusing on gamers feedback before releasing content - this is a good thing.
