I have a made a fair number of fruit wines, so I'll jump in with my opinion, you are liable to get several. First part, in addition to the TA Test kit, you need to own a fairly good Ph meter. One that is good to 0.01 Resolution. To me the Ph of the wine is important to make certain you are in the correct range for your yeast to work. 3.2 (maybe as low as 3.0, but not much lower) up to about 3.8. Most fruits you want to start around 3.2-3.6. Also, the TA test kit depends on a color change to determine you are done. I've never done it right trying to determine the color change, but we are in luck, it happens when the ph becomes 8.2. Don't know why the instructions with the test kits don't tell you that.
For most of my wines, I measure the Ph only pre-ferment and try to get it near the range I want, experience gives you that number, but for me whiter fruits are nearer 3.2 or 3.3 and darker fruits are nearer 3.5-3.6. Then I taste, if it is flat, I add a bit more Acid, small amounts. If it is sharp, I consider removing some acid. After fermentation is complete, I worry more about the actual TA and Ph numbers. Ph needs to be known to determine how much SO2 you need to protect the wine, TA determines how it tastes.
Now what acid to add, If I can determine what acid the fruit has primarily, I'll try to add just that. If not Acid Blend. I do everything I can to avoid MLF on fruit wines, some folks do it for apple wines, but I think it loses the apple taste.