Chewy, if you have any further specific querries feel free to send me a PM directly. There are three other Gen Nav instructors who regularly post here, and while I cannot speak for them I think they would say the same.
The advice is correct that there are a lot of CRP-5 questions. Although there are not that many questions specifically about charts, if you are having problems with Lambert's then it may affect some of the broader questions.
The concept most people seem to have difficulty with is convergence. Remember that although convergence is defined as the angle between two meridians, the reason that chart convergence is such an important and useful concept is that a straight line that crosses the two meridians has its bearing measured with respect to each meridian. Being a straight line, the only reasons that the measures of bearing are different is that the bearing is being measured w.r.t. different meridians. The difference must therefore be the angle between the meridians, i.e. convergence.
Best of luck!
Send Clowns
Gen Nav Instructor,
BCFT