I think adding andreas comment from 0001644 to the Delay comment is a good idea:
"A word of advice:
This is THE highest priority code which is run in Squeak, in other words it is time-critical. The speed of this code is critical for accurate responses, it is critical for network services, it affects every last part of the system.
In short: Don't fix it if it ain't broken! This code isn't supposed to be beautiful, it's supposed to be fast! The reason for duplicating code is to make it fast. The reason for not using ifNil:ifNotNil: is that the compiler may not inline those. Since the effect of changes are VERY hard to predict it is best to leave things as they are for now unless there is an actual need to change anything."