HAHAHA, Def hammer mode off grumpy...
I've never experienced or familiar with any "wavyness" caused by backlapping. If the reel is cylindrical this should not occur. When turning the reel backwards and applying cutting paste to the reel, the grit is worked between the two metal surfaces - one being perfectly cylindrical (the reel) and the other flat (the bedknife). This results in the removal of the dull metal cutting edges (reel and bedknife) leaving the entire top front edge of the bedknife perfectly flat and square, a clean cutting edge on the reel and perfect clearance between the two for the entire width of cut.
If there is any sign of a "wavy" bedknife as a result of backlapping I'd say there would be a serious problem with the cutting reel not being cylindrical. I wouldn't have thought that backlapping could cause a reel to become out of shape. If the reel is out of shape i'd say it would have been caused by a bad spin grind. In this case I would take it to be reground by someone who knows what they are doing.
Backlapping when performed properly should not cause any issues with the reel. The only negative of backlapping is that it removes metal. But if well maintained, only minimal metal is removed with majority of metal wearing from the bedknife. Bedknives are cheap ($40 - $60) compared to cutting reels (upwards of $300). Spin grinds on badly worn reels with rounded or dinged edges remove much more metal than a backlap ever would. If a sharp edge is maintained via backlapping the time between spin grinds should be greater. Backlapping may wear bedknives out quicker though this would be more ecomonical than frequent spin grinds. Removing large amounts of metal from reels with frequent spin grinding results in costly replacement of a reel.
