There is another really great site which may be very helpful as it is an interactive site that lets us get a really good look at things like plumbing as we can turn, zoom and choose all kinds of ways to get a better view of what's hiding in there!
https://catalog.winnebagoind.com/menu/Parts.htm
No experience with the Travato but I might think getting the panels off is really tricky. I'm guessing getting them off will first involve getting many of the fittings off!
I tend to like to gather as much info as possible when going into unknown things like this. I might try to figure exactly when and what makes the leak happen.
Is it when you put water down the drain or is it when we use the cold but not the hot, etc. as that can cut the potential leaker suspects!
If it seems to be a leak that happens pretty well all the time we are connected to pressure water, that can lean to ward a supply line leak? But if it leaks mostly after you drain a basin or take a shower that may lean toward a drain leak?
Try to sort carefully as that reduces the work needed to get panels off, etc.
Another small point might help if you are familiar with work on faucets? If you can figure the way to take the shower control valve off the wall, it likely will pull forward while still connected to the supply tubing! That may let you see or feel around the connections from the tubing to the faucet body.
I like to use tissue paper as a test item as it is easy to get in and let it show me if it finds water! Easier to spot than just a wet finger feeling around!
Maybe it is only a fitting that needs to be snugged up a half turn to stop a drip? Much better than removing the panels if we can get a wrench in to do it!
I was not sure which build RV you have, so this may/may not be totally correct but an example of what you may find?
Click this snip for better view!
The back of the shower faucet may be a real suspect for leaks in the supply as there are several fittings which may need a look and you "might" be able to get to them from the front?
Good luck on the chase!