it's a different source, a 10m grid (just see my attached image in the first post - it's a comparison between my sources and the ones you posted)
my question is:
2. I can apparently export it in SRTM 1" and 3" .hgt files which makes me wonder if this reduces that resolution or if it keeps it?
That is strange, as 1" and 3" are 30 and 90m grid, respectively. ( 1' is 1 nautical mile 1852 m, 1800/60 = 30 )
The known problem with SRTM artefacts remain ( woods, narrow valleys, urban canyons, rivers, bridges)
as reportedly tested by Brouter author, they have just better details.