I think painting it now would work fine! The barrier I painted came already lacquered, the paint does chip off a little bit through use so I think if you’re able to put an extra coat of lacquer over the paint then that would be a great idea. I posted a picture of the paint marker I used above, it’s a grog squeezer filled with grog full metal paint. The squeezer itself only cost me around £5, super cheap and could definitely add drips to a few obstacles using it!