it is possible your mac varie has too much built up within the plant. It would probably benefit from a week or two of zero. Other stuff probably would not appreciate it though. And if it's slowly bouncing back well, just keep doing what you're doing.
In my tanks during about a month when B and Zn were both in the .07s and dosing daily, several things began to melt at the stems down low; mac varie, myrio mini, didiplis and gratiola. So one or both of those caused problems at daily .07
At 4-5x per week havent noticed anything negative, but I still think it's too much.
I've been trying something new for the past 3 weeks- dosing higher concentrations only 3x per week
Fe - .3
Mn - .075
B - .06
Zn - .06
Mo - .002
Cu - .003
Ni - .0005
This is close to the old v13.15 that several of us were dosing daily at one point.
And I gotta say things are doing as well as ever.
Im trying 3x per week for two reasons, the convenience of going back to micros and macros on alternating days, and also because I have a theory about concentration and absorption.
As we know some of these non-chelated micros dont stick around very long. And we also know that concentration affects absorption. Higher concentrations make it easier to absorb smaller amounts. That's general biology, not just plants
So having .06 Zn for example, makes it easier for all plants to 'get enough' before it goes away in say a few hours (guessing on the time which is heavily related to PH)
Some things may not have access to enough at only .03 daily. .03 wont be absorbed as easily as .06, and it wont be around as long either
Also Fe and most micros dont have to be in a steady concentration all the time, like how its better to have NO3 and PO4 steady. Plants can drink up Fe one day and be OK for a while as long as they have plenty. So that's another reason
Its just a theory. After a while I may try this exact recipe cut in half and dosed daily to see if there's any difference. All I can say right now is a higher concentration 3x is working well.
And you're absolutely right small tweaks can make a big big difference. Who woulda thunk it??