Found the RID Combiner Force One Step Changers Optimus Prime, Blizzard Strike Sideswipe and Quillfire at Reiner Frütel Sport u. Spiel (an independent store that's a member of the "idee+spiel" trade association) in Duisburg-Rheinhausen.
[​IMG] [​IMG] [​IMG]

Optimus Prime is a new figure, Sideswipe and Quillfire are rebranded re-releases of existing figures.
This wave is also supposed to include Bumblebee (a new figure), Drift (a new figure) and Springload (another re-release).

There are numerous ways to count this wave:
– Robots in Disguise One-Step Changers Wave 12 (official numbering, Entertainment Earth)
– Robots in Disguise One Step Changers Assortment AS0H or AS0I (presumable alternate official numbering, BBCW Distributors)
– Robots in Disguise One Step Changers 2017 Wave 01 (hypothetical Big Bad Toy Store count)
– Robots in Disguise One-Step Changers Wave 9 (my own unofficial count that excludes waves that didn't contain any new figures)

This wave has thus far been sighted at retail in Australia and the UK.