It's a habit I started many years ago and I love it! I don't see a good reason to skimp on luxuries that don't cost much.
I sprayed the garden hose onto the roof and none of it reached the gutter before I felt like I was wasting too much water. It pooled in the lowest point which is the mid-point. Not what I had in mind when I asked for a skillion roof verbally and in writing, which is high at one end to ensure run-off. I don't yet know how the roof will perform under a big storm. Hopefully it will drain away and not leak through.
In time, the downpipe will be connected to a rainwater tank, which will water plants in the chicken run. We don't usually get much rain, so catching it and putting it to use is wise and new houses are required to have rainwater tanks, so of which are plumbed to flush the toilets which is fantastic - why flush perfectly good drinking water down the toilet?? That said, recently we've been getting more rain than I'm used to and it's been another very mild Summer so far. This coming week will be in the low 30s C all week, but that's not very hot, especially as the humidity will be close to 0.
There's never snow at my house, but sometimes there's snow on the biggest hill nearby (we call it Mount Lofty but compared to the mountains at your house, it's an ant hill

).