So Taylor Technologies, the gold standard held up by TFP has it wrong in their own notes about their own reagents for drop tests....... Technical FAQs ...CYA doesn’t interfere to cause a high reading on the TA test, it is part of the total alkalinity and should be accounted for. CYA, borate and carbonate are the major species that interact to stabilise the pH and are all part of the total alkalinity. If present, all three are accounted for as part of the total alkalinity test. Removing the CYA portion is an ‘old school’ pool industry thing, TFP does not remove the CYA portion, that would lead you to over dose with baking Soda and artificially raise your TA too high. Removing the CYA borate portion leaves you with carbonate alkalinity and is done automatically to calculate CSI.
Note i'm very happy to learn if they have just i would think that they would themselves know how they own reagents react.