R. v. Thombs, 2023 ONCA 850, December 20, 2023, at paragraph 13:

Courts have recognized a number of factors as relevant to the exercise of this discretion, including the reasons for, and degree of, the lack of compliance with the rules of the court; the prejudice, if any, to the Crown; the degree of disruption to the proceedings; the history of the litigation; the merits or absence of any real indication of a prospect of success on the application; and, justice and fairness to all parties: R. v. Greer, 2020 ONCA 795, 397 C.C.C. (3d) 40, at para. 112; Megill, at paras. 157-8. The trial judge referred to some, but not all, of these factors in her reasons for concluding that the application should not be heard.