A checklist of supported forms is something that's in the works. Right now the only supported type of income is W2 wages.

The reason I chose React is I wanted the site to be client side only, fitting with SPA, to avoid having a database of social security numbers that could be breached.

Typescript is being used to help make sure the right types are being used when the form is submitted. Income should be in number format & names should be in string etc. I've also just found it pleasant to use