Blade tape is legal for the 206 and always has been.
Without it, in the European wet climate the blades will struggle to make TBO.
The rub is that the tape is expensive and doesn't last long.
We used to tape from new and stop at about 2/3 blade life. No point in putting tape on a blade that is heading for the scrap bin.
Not sure what the Bell 206 MOM says it about it these days but we used to apply tape in one foot sections over the prescribed length.
There were two benefits, firstly if a section split it was easier to replace and secondly the loss of a section had little effect on the flight characteristics.
Bell recommened putting on one long strip several feet long. Great fun when it started to peel off in one big piece.
The MOM limits are large and if the engineers are saying it's within limits then I am sure that is true. Could be the blades are not far off their scrap life.
Trying to tape a badly erroded blade is difficult and often not successful.