I did this when I grew inside and got good results. Pro tip though don't just use white clover, you want biodiversity. I use a mix it's got a few different species of clover plus flax, cow pea, and some others I don't remember.

Cover cropping has myriad benefits. It "probably" doesn't matter "as much" in a container but it's pretty and it's certainly not hurting anything. How big is your container? Do you have one for all your plants, or one for each?

The issue i can see is moisture and nutrients, but if you are watering and feeding on the regular i can't see why it would hurt? Maybe holding too much moisture against the base of your grow?

I personally wouldn't do it. I don't see any benefit from it, other than maybe looks. But I would be worried of some fungus or mold growing underneath. In my last grow, I actually had some fungus. But I could spot it fairly quickly.

That being said, we are all not professional gardeners, but learning from experience. Do what you feel comfortable with. And if you grow a wicked weed, share some!