Dulux Easy Care Matt

I have a customer who is insisting I use this retail gear on her property, it's an entire house 4 bedrooms, 2 staircases, all newly plastered. I have a suspicion this is going to cost me a lot more, both in time and materials , the original spec was a mist and 2 coats of Covaplus.
Anyone used it ?, because if as I suspect it will be a complete ballache, I'll tell her to get someone else
Thanks in advance