Suggestions To Model Rocket Companies

I've brought up this first idea before -

VISUAL ENGINE DESIGNATIONS
Suggestion: Print the Engine Designations (B6-4, C6-3) around the lower 1/4" of the engine casing.
On most models, the engine sticks 1/4" out the back end of the engine mount.
This would make the RSO's job a whole lot easier at check in. The RSO could read the engine type instead of just taking the flyer's work for it.
We've all witnessed a rocket coming in fast when a newbie used the wrong engine or too long a delay. A quick visual check at check-in might have led to a correct engine recommendation.
This could be a big safety improvement.
I worked in a print shop and am aware of "image area". Some printers (maybe the engine printers) might not allow printing so close to the nozzle end. The designation wouldn't be a full color band. These printed paper bands were glued onto the nozzle end for a visual example. 

EXTRA TEST DECALS
Suggestion: Add a few small duplicate decals on the water side decal sheet and mark them "TEST".
This gives the builder a chance to check the soak time and transfer.
Most kit supplied decal sheets have just enough decals to decorate the rocket.
The builder has only one try to get that first decal right.
This could save the manufacturer from having to send out replacement decals.

SPRING STEEL ENGINE HOOKS
Some kits include an engine hook that gets get bent out of shape after the first flight!
Spring steel, not pot metal. You can get spring steel engine hooks from BMS.