Slab Reefing , Ready to Go?

[Scare_Rab]

bought a nearly finished 33' yacht. Had never been sailed. Main-sail reefing had never been sorted. A rigger just brought my boom back, see photo attached.
Cost alot of money to have that winch attached, those line-stoppers attached, those slots cut and those cleats attached.
Looks ready to reeve the 3x reefing lines though.
One thing, the rigger suggested a " reverse-about " reefing.
1. lower main halyard to approx position 2. Haul leech line and bring reefing cringle down to boom BEFORE 3. tensioning halyard.
He says it always easier to do this way.
Any people here do this?