Just discovered this topic. I’m the main dev of cartes.app. We used the .de instance, until we found out about it being drowning. So we started our own. Then we went to mutualize our instance with the French community on osm-fr servers, discussed on the equivalent forum.
Now we’re drowning with both our load (that we’re optimizing right now), and the external load from multiple actors 
Setting up the instance wasn’t hard using the online guides, but we’re suspecting it doesn’t use most of the VM’s resource.
We’re especially suffering from the meta requests being heavy (2 seconds vs 20 ms on the same simple node request). Searching for these keywords led me to this thread 