Starting at about the same time as the conquest of Crete, however, requirements for membership in the Janissary corps were being weakened throughout the empire because of pressure from the many citizens (of all faiths, including Islam) who coveted the educational, economic, and political advantages they could gain as Janissaries. Many Cretan Greeks changed religions to make this move. The Janissaries seem to have become integrated into the local economy, rather than remaining separate as they had in the past. I don't know if the policy that designated the corps as the sole inheritor of every Janissary's estate remained in effect, but I wouldn't be surprised if that was weakened also.
Busy as they must be, I owe them thanks for the sketches you'll see if you look at the Janissary fashion show below. They don't say where they got the pictures; the style looks Turkish, but there is Western handwriting (probably German) on the pages.