What is the test for severing a third party proceeding?

The key factors engaged in a general sense on an application to sever were canvassed in Schaper v. Sears Canada, 2000 BCSC 1575 [Schaper] at para. 19: 1. ...the party making the request must show that hearing the claims together would unduly complicate, delay the hearing, or otherwise be inconvenient. If a party applying does not meet this threshold, the court need not go further in any analysis and the application should be dismissed. 2. Have the actions of any party in the proceeding been unreasonable and have they contributed to the complication, the delay, or the inconvenience alleged by the party applying? If this found, that would strengthen the argument to sever. 3. Are the issues between the plaintiff and defendant and the issues between the defendant and the third party sufficiently distinct so as to allow them to be tried separately? If so, that strengthens the argument to sever off third party proceeding. 4. Is the relief claimed by, or the potential obligation of, any party best determined by hearing the evidence of all parties at one hearing? If so, that weakens an application to sever. 5. Does the prejudice to the party applying, prejudice based on undue complication, delay or inconvenience, outweigh any benefit of matters being heard together, or outweigh any considerations related to the overall objective of the rules to ensure a just, speedy and inexpensive determination of every proceeding on its merits, including the avoidance of a multiplicity of proceedings for the benefits of litigants and having concern to congestion in the courts generally?