You would think so, but in fact the unemployment "insurance" agencies of some (many?) states are overtly hostile to using your time to build a startup rather than unsuccessfully seeking a position as an employee.

In Connecticut, for example, the statutes say revenue from self-employment should offset unemployment benefits, but the state agency has chosen the highly creative interpretation of "revenue" to include potential capital gains your efforts represent, and the notional amount of salary you should be paying yourself for the work you do for your startup, including, say, writing a business plan.

It does seem like they are shooting themselves in the foot, but the unemployment "insurance" fund in CT is already living on debt.