Am 15.12.2017 um 16:11 schrieb C R:
Inkscape's speed/increment modifier convention is currently:

Alt = slower increment
Shift = faster increment
No modifier = normal (default) increment

We should definitely keep this consistent wherever it's possible to do so.

My 2p.

And where can I find a control in Inkscape that follows this "convention"?
If we have a convention I'm totally fine with sticking with it, I'm just not aware of any (and if there is none I personally prefer Ctrl over Shift over Alt).
If there is a convention it first of all needs proper documentation, so a) devs are aware of it and have a chance implementing it and b) users will have a chance of being aware of it and use it.

The only related thing I could find: While moving objects around and doing similar tasks we sometimes allow:

Maybe you were referring to that? With the confusing behavior it's hardly a convention either, though...

If in the end we really have no convention it might be a good time to think about one!

Best Regards,