No, and it's a royal pain, as I need these flights quite frequently.

The only way to get the discounted fares, I find, is to phone KLM e-services to report a 'failure' in the online booking engine (which is true). They'll then go through the motions of booking it, find the fault (yet again) and book your ticket over the phone.

This avoids the offline booking supplement, and lets you get online-only fares.