I'm playing with full bob and angel.
I had a look at the function retroactivate and did some printf debugging. All the recipes are found and enabled is set to true. Maybe it is a problem with Factorio itself, if I remember correctly one should not unlock recipes in the on_configuration_changed event but use a migration script for that.
Since you already search for the correct technology that unlocks a bot you could add the disassemble recipes also to the recipe unlock effects (in a second loop that only runs in hard mode). Then these recipes are hidden until the research is completed. The powercell and control unit can be unlocked via the base game robotics tech, since this is always mandatory to research (even with angel + bob).
The actual unlocking can be done via a migration script with just a few lines of code:
for index, force in pairs(game.forces) do
force.reset_technology_effects()
end
But despite my problems to get it running: The mod is really great :)