Hi can anyone tell me what's the current 'state of the art' with regard to a baseline toolchain for OS4 development (and ideally OS3 ?)

For example, aside from installing the official SDK, is there a common agreement on:
- a newer version of GCC that everyone is using for their projects
- newer version of newlib available somewhere?
- newer version of clib2 available from sourceforge?
- other popular libraries that are defacto part of an OS4 developers toolkit?
- extra tooling everyone is using e.g. sgit, memguard, others?
- header files with macros to make it easy to share code between OS3 and OS4 e.g. hiding interface pointers and allowing the same universal primitives to be used on each?

Additionally, same question but aimed as cross compiling toolchain? I have got adtools setup on linux, but I understand there's docker images to be found somewhere and actually that might be a better way of doing it?

Finally and additionally, same question but aimed at OS3 development. I know there's supposed to be a new SDK coming with 3.2, and while I have SAS/C it would be nice if there was a reasonably recent version of GCC and clib2 for OS3 that everyone is using to make it easy to collaborate without everyone having their own slightly different set of headers, libs and tools. So is there one?