The fun thing with papers is that development is pretty much self terminating, so you can't overdevelop.
For RC paper, the regular development time is 60 seconds. But after 90 seconds, nothing happens.
Underdevelopment will mostly affect the maximum density of the paper, something that can lead to either too long exposures, unwarranted grade changes and general impossibility to replicate a print.
The grade of the paper to use will also be affected by the enlarger as condenser enlargers produce more contrasty prints by design.
Also, matte paper often seems to need more contrast while glossy seems to need less.
The light you show the prints under also has a huge effect on perceived contrast...