I suggest changing the desc of the flag from Rendering based on the Anti-Grain Geometry Rendering Engine library to Switch rendering from OpenGL to the Anti-Grain Geometry Rendering library so you immediately know that otherwise OpenGL will be used. Should not be an issue as the useflag is local only.
it might become global later. Also I expect other renderers to be added to gnash (if there are not already) so I do not want to focus that, sorry. Thanks for the suggestion tho