Looking around some, and I think it's japanese tree lilac / Syringa reticulata. One volunteered in my yard. Unfortunately, too close to the service berry, which I like better. Off to find the hacksaw.

NO! Do not do a rejuvenation to any Viburnum!! Michael Dirr, who wrote the book on them and who has developed many of them, recommends infrequent and light pruning of Viburnums, if any at all. This is my favorite shrub. I have at least two dozen and about 8 different cultivars. I believe the one you have is a Burkwood, but it could also be Judd. Either way, it's gorgeous, pretty much pest- and maintence free, and you should definitely NOT coppice it. You do that to a Rose of Sharon or a lilac, but never to a Viburnum. Here is a link that might be useful: Michael Dirr's Viburnum for American Gardens

did anyone identify the large yellow shrub on the battery in Charleston SC?

Small woody invasive species I pull out by the roots with a large set of pliers. There are also tools designed for pulling woody plants typically called something like a weed wrench that can be used for things a bit larger. If you cannot pull or dig it out, cut it to the ground after which you have a couple choices. For Japanese knotweed and larger woodies, I cut down and paint stumps with a brush strength herbicide. I am not an indiscriminate user of lawn and garden herbicides, but in this instance I think it is the lesser of two evils, and since I have more than 100 acres with lots of invasives, this is my only hope of removal. I have researched to find what won’t stay in the soil and wear protective equipment. Painting on cut stems uses less herbicide and in a very targeted fashion. Alternatively, cut them to ground level and then religiously check for sprouts every week or so. Remove the sprouts. Continue this for a season or two, or for Japanese knotweed, it might be longer. This will use up the plant’s stored resources without allowing it to replenish. But it only works if you are very, very consistent. IMO removing invasives from public land that adjoins your property is totally reasonable. But as I said above, don’t remove until you have a positive ID.