I believe that the contract for the frigates included upgrades. So if Taiwan wanted to upgrade her fleet of frigates with the 16-cell MICA VL launcher then that would be looked at as an upgrade and would fall under the original contract.
A TC-2 vertical launch system would be nice but it would take too long to build a vertical launch system and modify the missile for use on ships. Since the MICA is already in service with Taiwan and is a very modern missile I believe Taiwan should upgrade her fleet with this missile and ditch the Chaparral systems.
Really, Taiwans only real choice is to field a TC-2 based VLS or stick with a US System. IMO:cool: