What kind of breaking changes would it make sens to introduce in 1.0.0?

[MateuszKubuszok]

Since 1.0.0 would set API in stone it would make sense to clean up before the release whatever we already see as clumsy or user unfriendly.

Some changes that I can think of:

• shorten names e.g. withFieldConst -> fieldConst or setField, withFieldComputed -> fieldComputed or updateField (the later being inspired with lenses, since it is a very generic lens, kinda)
• rename Coproduct -> Subtype since it something more people would understand
• replacing partial.Result name with something that works better with IDEs
• adding a flag to make recursive derivation optional, and setting it to opt-in

What else would be a good candidate?

[MateuszKubuszok]

It seems we managed to avoid most of the changes so far, only addressing (in a backward compatible way) rename Coproduct -> Subtype since it something more people would understand.