Hi Marmar49,
A bit of clarification might help. In the original post you linked, the OP seems to want to make transaction non taxable when a specific tender is applied. But in your post you are asking for a transaction to become non taxable when it is classified as a "togo" order, which is either being achieved by order type or revenue center, depending on how the system is set up. IF the latter is true and you dont care about tenders and only want for instance the togo order type to adjust the tax that can be done by changing the tax class that its tied to the order type TOGO to your tax rate that is set to 0 then maybe inroduce a new touch screen button that changes between order types thus changing the tax class / tax rate and you're good.
Hope that helps. Feel free to ask any questions if this wasn't clear.