in my opinion, this time depends on the cumulus oocyte complex maturity. The mature one may be stored before fertilization maximally 12 hours, in other case, the in vitro maturation should be started immediately after acquiring and I recommend carry the ICSI out in 2 hours after meiosis II at least. Long delay may damage the developmental ability of the oocyte.
The oocytes are generally retrieved 36 hours after hCG injection. It has been reported that fertilization and embryo growth are optimum when eggs are injected within 3-5 hours after retrieval. Later injections may fertilize the eggs but embryo quality is affected. This decision on denuding has to be made on the appearance of COCs. If egg is at MI, it may become MII in a few hours. However, GV will need 24 hrs. In a reported case of non availability of sperm at retrieval, the eggs were kept until the next day when sperm were available through TESE. A live delivery was reported. If you need reference, I can send. Murid Javed