[PROJ] Serious confusion regarding towgs or not...!

[Nyall Dawson]

Hi list,

Been struggling through fixing some QGIS proj 6 related issues today,
and I've got to admit - I'm very confused about the role of towgs84 in
the proj 6 world.

My current crop of questions:

1. Is towgs84 effectively deprecated? Should I be avoiding it as much
as possible? Is it inherently evil?

2. When I identify various WKT definitions using projinfo, I get a mix
between direct matches and matches to "BoundCRS of ...". I'm unsure
when this BoundCRS is important or not. Should I be treating a CRS
identified as a BoundCRS of ... as identical to the identified CRS,
and is it safe to just use the identified auth/code combo for that
CRS? Or is that losing important information and I should NEVER treat
a BoundCRS identified match as being an identified result in any
circumstance?

Thanks,
Nyall