That’s all nice and good but I don’t see compressed PNG size as being that big of a deal. It might make the apk download slightly slower, but I haven’t heard of that being a big user acquisition problem until you get into the dozens of MBs, which is probably only an issue for game apps. Most phones these days seem to have enough space that an extra MB here and there isn’t that big of a problem.
I think the bigger issue is once you uncompress the image and load it in memory. That’s where a lot of image problems happen around memory utilization. A tiny PNG can inflate into a giant memory hogging monster. That’s where your standard Android tricks, like providing multiple resources, can save the day.