It shouldn’t happen regularly but I think it happening occassionally is a good thing - keeps things a bit more random than just having them appear every 7th episode or so.
Of course the big mistake Seven have made is having too many Chasers now - adding the last two was completely unnecessary and smelt of panic in the face of new competition. The three originals plus Cheryl and Mara felt about right, especially if they’re continuing to have a couple of British chasers involved too.
Talking of panic and wonder if Seven might consider some family episodes in the 5pm slot where all four contestants are from the same family. The UK versions did a couple of series of The Family Chase - it’s not been back for a while and the original format is stronger but if they wanted to do the odd week of something different I think that’s a better idea than the Double Trouble weeks.
Overall though the best thing Seven could do to give the show a boost is commission more Beat the Chasers for primetime - considering how well 1% Club does I think it would probably do OK for them, but more importantly it’s an hour long primetime promo for the daytime show - although knowing Nine they’d counter it with Celebrity Tipping Point.