Ok, go to court with evidence from Facebook? Especially from the ex's facebook page. How easy is it to turn that into stalking?
So everything you present to the court is read by the solicitor. That is gonna cost. So keep it short.
Whether or not you can 'prove' that mum works or parties at the weekend are irrelevant. What is relevant is 'best interest of the kids'. The common territory these days is a mix of weekend and mid-week time. That is what you're proposing. So you're on a win.
Sure there is a conflict between you and the ex. If there wasn't she would not be your ex. She would be your partner. Keep this stuff simple. It isn't like she wants to raise them Muslim and you want to raise them Christian. You just disagree about when they should live with dad and when they should be with mum.
So keep it simple. Forget he said she said... That said, I reckon you can include in your chronology in the affidavit the dates that she has failed to meet on Sunday. Let me emphasise this. It is not your job to prove she is out partying on Saturday. Big deal. It is your job to explain why Thursday- Monday morning is a win.
forget how toxic the relationship is. Big deal, of course, it is toxic. It really doesn't matter.
Just focus on why your proposal is a good one.
Here is a link to a good website that explains what substantial and significant time is BTW the terms substantial and significant time appear in the legislation. I'm not making this stuff up.
What is Substantial & Significant Time with Children and when is it Ordered – DIY Family Law Austraila
So let me repeat myself - just focus on explaining why Thursday arvo - Monday morning once a fortnight is a good result of the kids. Your affidavit needs to focus on that, not facebook. Not work rosters
Cheers