We tried posting one of our games on CrazyGames and when looking things up for it they recommended the URL restrictions. It does mean needing to maintain a list of all the possible domains for anywhere you want to host, but once setup it shouldn't be too bad. For basic jam games we don't currently bother, but it is on our list to add to our template so it is always available when we need it.
Having extra pieces that make testing easier is often good, especially early on. We have plenty of debug extras in our games, with only some of them exposed for testers who know where we hide them (5 quick clicks on Development Preview to unlock and 1 more to open the unlocked menu). While trying to figure out the camera stuff I agree that the 2 camera approach is a good one. I can see how having both be cameras can make it easier to compare things when the math doesn't seem to be working. I'd so much rather be able to switch between the views and see how they compare than just look at the math and end result. You seem to be on the right track, experimenting with different ways to do things to find what works. Personally, the only issue I have with the current system is the small hops interfering with my jump timing as I approach an edge.