Yeah I think weekend CPL modules are viable. As people have said its largely a matter of finding a school/instructor willing to do it. One of the great attractions of teaching for the Commerical ratings is that its mostly 9-5 Mon-Fri....
Also by not being on the full time regular course you will miss on the opportunity of bouncing of fellow course mates. This is invaluable as inevitably fellow student on the same course can often convey some element of the course better to you than any instructor. Fellow studes also provide a useful morale boost, incentive and their comradeship makes the whole process more of a positive event.
Good luck,
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