Image size questoin...I promise it's different this time

As a designer, I usually work with images without much regard to their resolution…only thinking as long as it’s high enough I can always make it smaller. Later on down the design road, there’s a time when I start thinking about proper image resolutions. Outside of reducing image sizes by brute force by finding each image, reducing it, then replacing each one by hand… I’d like to know if blocs has a way to automatically replace images with their smaller versions? How do you guys do it?

Blocs doesn’t have anything inbuilt (and I don’t think it should).

I have used and still use several apps including…
Pixelmator, Affinity Designer etc.

I’ve also relied a lot on this web app. Once I have the resolution I’m after I’ll often run it through this.