very shortly you will be trying to tell me that english polkas which are in 4/4 which have less notes than reels are faster than reels.
I have the matt cranitch book i know him and jackie personally, i have booked them for 8 years at my festival.
Jackie daly made a statement if you have a problem or do not understand it contact him.
when reels are played in sessions after other tunes they have a dynamic impact, this not just due to change of tempo but because they are faster. example changing from jig to reel , it rarely wporks the other way round reel to jig.
I cannot find your quote in matt cranitch irish fiddle book anywhere, what page is that on ,
what he does say about polkas which is much more important than your rremarks is that the emphasis or stress should be on the off beat, this is what is important in irish music the emphasis, there also is an emphasis in jigs which can never be notated properly in music notation, where it looks to be even but it is not there is an emphasison beat and to a lesser extent beat 4
do you play a melodic instrument matt?