Flipping Dynamic Lighting Polygons?

Just recently got back into Roll20 as all of my gaming buddies are quarantined due to the virus, and I'm trying to utilize a dynamic lighting map I purchased on the marketplace (Dynamic Dynamite: Blood Shrine, very well done). The issue I'm running into is that when I pull the map pieces onto a larger VTT page to puzzle them together for a larger scale dungeon, I've had to rotate several of the maps to make them fit (seems like that's how it was designed to be done anyway). The problem lies when I attempt to do the same with the predrawn dynamic lighting polygons. I can copy and paste them just fine, but I can't seem to flip them to make them match up with the actual map drawings. Is there a way to do this that I'm not privvy to, or do I need to redraw all of the dynamic lighting myself? Follow up question, if the latter is the case, what is the point of purchasing map packs with predrawn dynamic lighting if I'm going to need to redraw a good deal of it anyway?

You can't rotate the dynamic lighting lines.  I consider this a bug, but is the way it has always been, so at this point it's a feature enhancement.  It is possible to reconstruct the Dynamic Lighting lines in a proper orientation with the API (a Pro Subscriber Perk). As for the value, it's in using them in their existing orientation I suppose.  Which marketplace product are you using?

It was a map pack called Blood Shrine by Dynamic Dynamite. I said it was well done in the original post, but honestly after going through it there are some issues. You have to scale down the gridlines to .5 in order to match the ones drawn on the maps. This makes any tokens dropped onto the map rather blurry and tiny, imo. The other option would be to increase the size of the VTT and scale up the drawing, then the dynamic lighting, then the gm underlay layer...  bit of a hassle, so I'll play with tiny character tokens. Honestly though, now that I've gotten a bit of practice, drawing the polygon lines manually, while tedious, isn't that big of a pain. I know nothing of programming, so I don't know where the hang up in rotating grouped objects lies, but c'est la vie

The issue is a flaw (or optimization) in the way the dynamic lighting lines are used to calculate the boundaries, which only takes their shape and location into account, but not their rotation. The API method of fixing this is to apply the rotation to each of the points that make up the polygon and thus create a new polygon with the original's shape but in the desired orientation without needing a rotation.

Would it work to move everything from the map and DL layers to the GM or token layer,  do your editing/rotating,  then move everything back to their original layers?  Or,  just start by working on the token or gm layer,  then moving everything?

Nope.  Moving objects between layers is just a property change, it doesn't change the underlying structure.