Just a few words regarding your advice not to buy Reolink:
I had read your valued advice before buying these cameras and was therefore trying hard to avoid them. But at 100 EUR for both new RLC-420-5MP I just couldn't resist the offer on Ebay including shipment from within Germany. And so far I have nothing to complain about.
I like this kind of housing (similar but smaller than the YCX 5MP cameras I bought back in 2015) The video quality is really excellent and by far better than any camera I ever owned before even in low light conditions with 3D-NR enabled.
There is one thing that I wasn't aware of before I bought them and that was the limitation of resolution settings. Reolink only allows to select from the following resolutions: 2560*1912 / 2560*1440 / 2048*1536 / 2304*1296 on clear stream (or 640*480 on fluent stream). First I was a bit disappointed because of the missing intermediate resolution settings but then I tried 2560*1912 with 4fps and it gave me very good results.
I have not tried the integrated memory card function yet and I am not shure about the audio quality but that's both not my main concern. At this low price I won't be angry if the lifetime of the camera turns out to be only a few years and if perhaps there will be no support or firmware update. I never received any helpful support for any of the cameras I ever bought before except from this forum.