I didn't realize that you would do an MLF on a white wine? I thought that was only for reds? I've never looked into this process because so far I have only made Chardonnay's and Gruner Veltliner.
All of the chards I have done in the past I have stirred every few days while aging on the lees. I haven't gone any longer than 4 weeks or so as I'm afraid that it will pick up too much of a champagne/yeast taste. Maybe I'll pick up another one of those $44 dollar Vino Italiano chard kits from Amazon and try battonage for a few months. The one I made previously tastes like poison. But that my be my fault as I only made it into a 5 1/2 gallon kit instead of 6 for fear it was going to be watery. It's only been in aging for a couple of months so maybe it will come around yet.
To get that heavy buttery taste in a Chardonnay, you do an MLF. Lees aging gives a little of the buttery feel, but not so much the taste.
Of course one should never do an mlf on ANY kit wine, white or red.
Chard is a popular wine for MLF. It also takes out the bite, similar to what lees aging does, but even more so. MLF converts the tart, malolactic acid (green apples have lots of it) to a much smoother lactic acid. The butteriness comes from another chemical that gets produced during MLF.
It is somewhat unusual to stir lees everyday, but that doesn't make it wrong.
Some pros stir once a week for a period of time, then go to once every two weeks, then once per month. There really is no wrong answer. I think cutting back on the stirring allows you to leave the wine aging on the lees longer.
I have found that lees aging for about 4 months, stirring once a week really gives the wine what I like. That's just my opinion, though. I think one can over do the yeasty flavor, myself.
Of course I would taste each week just before I stirred, so I could get it just the way I like it.
Lees aging and stirring tends to dull the fruitiness of a chard.
For thinness in the chard, use some gum arabic or glycerin. I think both of these products can do wonders for a kit wine, especially reds, which tend to come out a little thinner than their commercial counterparts. Other than a Pinot Noir, I just don't like the mouth-feel of a thin, watery red.