Unsure about drop kits, but with comparators and (basic) photometers (ie DPD reagents) you can test the bromine residual using the chlorine DPD reagents and multiplying the result by 2.25 for a bromine residual, hopefully someone with knowledge of Taylor Tests can confirm or decline if it works the same way.
If that is the case, you wouldn't need any extra test equipment whatsoever, as for the test strips either throw them away, or take tests with them after using your Taylor and laugh at how horrendously incorrect the results are.
Edit > if you do decide to change to chlorine (bleach) you have a ready to use, balanced and disinfected supply in your pool that can be used to fill the spa with, it saves balancing two pools of water