Re: Is there a way to upgrade only packages with substitutes?

[P]

> This option will update only packages with substitutes and very small 
> packages without substitutes (if they compile quickly). And it will not 
> update big packages without substitutes. Realization of it we cannot assume.

How can you know what compiles quickly? Stats based on previous versions? What 
if someone is bound more by memory and/or storage than time?