I can confirm that PUP detection does work on avast.
About 2 weeks ago, I first ran an MBAM scan on my sister's computer. It found a little over 200 PUPs.
Then I ran a SAS scan and it found around 70 PUPs.
By that time, I figured all the possible PUPs in that computer would have already been found and removed.
But, I then ran an avast scan and it still found I believe 13 more PUPs.
Then last week all those 3 Apps again found more PUPs and a few Trojans.
Yeah, that computer is a mess. While my sister doesn't use it at all, my brother-in-law, his daughter and a niece of mine do use it and they obviously have some very unsafe, unwise and ill-advised browsing habits. They're App installation happy and are the type who just click on Next Next Next without reading anything.