State of DIP 1000

[Dennis]

How is DIP 1000 doing? The document [1] says 'status: draft' and 
'pending a rewrite', though there already is an implementation 
behind the -dip1000 flag and I've seen people using it. How much 
is implemented? Should I already compile with it and use scope?

The last forum thread I found "On the future of DIP1000" [3] is 
from 2016. What's the current roadmap?

Relatedly, can I already use 'in' for function parameters?
"It is recommended to avoid using in until it is properly defined 
and implemented. Use scope const or const explicitly instead." 
[3] Is that up to date?

[1] https://github.com/dlang/DIPs/blob/master/DIPs/DIP1000.md
[2] 
https://forum.dlang.org/thread/taqkzwiezkfylxjinozg@forum.dlang.org?page=1
[3] https://dlang.org/spec/function.html#param-storage