What constitutes an inconvenient developer?
Most inconvenient: Buying measuring equipment, various discrete chemicals, then mixing it up yourself.
Less than convenient: Developers that come in powder form, premeasured.
Convenient: Liquid developers, including PMK premix.
Since the majority of the process isn't mixing the chemicals, then the most important thing is the effect of the developer on the film. As for precise controllability, heck, I use a Holga a bunch! I'm happy when something actually shows up on the film. Arthur Fellig (Weegee the Famous) commented that you shouldn't be a "chem head." Pick something and just stick with it.