Nope. The debugger is awful. However, writing OO code in classes means far more code re-use, and far more focused, shorter code sequences to debug in future.
So you tend to debug more. We have tons of run-time diagnostic stuff too (as our product is meant to be used in secure environments) meaning that since we have more state information during every single cycle, debugging is far easier.
(or so we've found. The 160,000+ lines of Lotuscript in FirM are over 10 years old, OO based and - I'm rather proud to say - still working)