And this would lead to people cashing out all their bonds for gold on tax day, so they would never have to pay the taxes.
No.
And this is different from how people usually play how? The only bonds I ever have are the ones from taxes while on campaign. Also, if someone hoards golds instead of bonds, they get taxed for gold. If this change were implemented, while you may be able to hoard gold for all eternity if you were to get outside the reach of the taxman for gold (which, from what I have seen, has only been suggested for prison), you could only receive bonds as you would more than likely be outside your duchy and thus receiving bonds anyways. Which would be taxed.
