The saying was always “whatever you can do going forward you can do going reverse and whatever you can do on side you can do offside”. Of course some of those maneuvers are more for show than practicality. In fact practically speaking you never have to change sides anyway to go elegantly in any direction you want. Mr Galt felt that way about solo paddling.
Actually, I have always thought in solo flatwater paddling the only offside stroke that is necessary is a cross forward used from a complete stop to quickly attain speed without losing direction. But remember that before the freestyle movement began touting itself as technical paddling, the whole entire purpose was fun. Period. Still is for me.