Well... its my turn in not understanding what you do/want to do
OSC is working throw 2 different ways:
1) something is defined in the pattern file, here you specify exactly what you need, toggle or binary (as in my example)
2) when you "Learn" in the actions list.
I have just tested the way (2) and I get "toggle" effect for "Transport: toggle repeat", no matter with or without value.
But in case you use the same OSC path ("/repeat") in both places, you can get strange effects since corresponding actions are executed twice when the command is received (so "OSC leaks" like "MIDI leaks"... it seems like that is Reaper philosophy to allow users do stupid things...).