What is the current state of the law on interim custody and access matters?

With respect to interim custody matters it was held in Thibeault v. Ravelo, [1999] B.C.J. No. 1457 para. 15: ...there can be no absolute rule that Master’s decisions on interim custody and access matters are purely interlocutory and should not be interfered with on appeal unless established to be clearly wrong. Interim rulings concerning custody of children or access to children must be examined on a case-by-case basis to determine if the interim ruling will likely have a direct bearing on the disposition of those issues at trial, bearing in mind the specific issues and the length of time the interim ruling will be in place.