I think the reason some people advocate moving back in to the house is because the fines for illegal eviction are very high and the PRTB give these cases priority (upto seeking injunctions on behalf of non-paying tenants: very costly business for the landlord even if he were to somehow win the court's favour!). Moving in is clearly a breach of contract but I don't believe the PRTB fasttrack such issues nor seek injunctions, because nobody is on the street.
The advice to follow the system is easy to give when it's someone else who has a property in neg equity, with mounting mortgage arrears and no way of paying them unless their tenant does the decent thing, pays the rent or leaves. A person could quite easily see their house lost due to a bad tenant, the question at this stage is what risk is bigger etc. and it has to be looked at.
Even if the OP follows the procedures to the letter and the PRTB finds in his favour, and then he can go to court (because the PRTB won't do that for you unless you are a tenant) and then eventually gets an order for possession, he will NEVER get any money back from this period, which could easily add up to 20 or 30 anyway.
I see moving back in as a middle ground tbh.