Helping the kids: Student loans.

I have two kids starting uni this year. They both have part time jobs and I make them save 20% for their future selves, they are sitting at about $5K each.

We've been talking about the future and how I can support them through uni and have them not graduate to a working life with a huge loan.

I've landed on paying half of their uni fees if they pass AND if they save and pay for the other half.

The 20% they have been saving will be now going towards their fees bc I feel its unrealistic for them to save more than that given their living costs

They will pay their share of power/water/internet, and already pay their phones/gym/insurance/cars/bus. I don't expect rent, and will cover the shopping cost for food at home.

Going forward and given student loans are interest free is it better to invest their savings (and my half of fees) then pay back the loans once they start working? This feels like a no brainer but wondering if you guys see any trip ups besides the potential for a poorly performing investment. I know very little about investments but could put in into something like investnow.

This is not a parenting post. Please don't come at me about 'they should be paying board and stand on their own two feet'. I was raised like that, and actually it sucked.