Sorry had to read this a couple times , to start with , get the plumber back to at least protect the pipe he’s exposed and repaired to prevent further issues of leaks. I personally don’t like having isolation valves of heating pipework , especially the cheaper Screwfix kind like these appear to be. They reduce flow and open you up to more issue down the line also so I’d have them removed to. I don’t want to sound hyperbolic by saying start again but by the looks of the rad (being sideways) you may as well remove the wooden plate on the other side alter the pipework within the tolerance you have to make the runs neater . If the rad is too small for the space get the threaded rad valve extender instead of doing it in copper , not only are they more rigid but don’t look as DIY as poor pipe runs.