I develop Ektar 4x5 in batches of sixteen sheets. I develop then rinse for a short time then store them in Yankee tank immersed in water until I am finished developing all the sheets.
Then I wash the entire batch for Five minutes then dip each sheet in the stabilizer for minute.
Question: Am I going to have an issue waiting for such long time (up to one hour) before I wash and stabilize.
It'll be totally fine. The stabiliser is there to prevent fungus etc eating the emulsion when it's in storage, and it will work just as well after the emulsion has been wet for a while.