Leafgro is a wonderful, locally-grown product, but don't use it as mulch.  Leafgro encourages plant growth, so if you use it as mulch weed seeds that fall on it from the wind or birds likely will germinate and spread--not what you want!  Instead of laying on top, use it as a soil amendment and mix it into the ground.  Here's a little more info: https://ask2.extension.org/kb/faq.php?id=416945

Shredded hardwood is terrific for mulch, and, yes, perennial plants will grow through it.  If you're applying it now to perennials that have already emerged, place it around the base of the plants rather than covering them with it.  Here's more info: https://extension.umd.edu/resource/mulching-trees-and-shrubs

Bob

Leafgro definitely is compost and used as a soil conditioner.  You are right that the 2017 posting that I linked to did mention using it as mulch, but the Leafgro site itself recommends against doing so:  "Can Leafgro be used as a mulch?
Yes, but we don’t recommend it because mulch is used to suppress growth and Leafgro encourages growth."  See https://menv.com/leafgro/faq.html

I totally agree with that "yes, but" advice.  Yes, you literally can use compost as mulch, but the better practice is to use a material that won't promote weed growth.  In my own view, shredded wood bark is the best product to use for mulch.

Bob