[Toybox] Init -waitfor?

[scsijon]

BarryK of Puppylinux's origins has been having a problem I think may be 
worth sharing. 
(http://bkhome.org/news/201802/experimenting-with-busybox-runit.html)

It's basically because:

"Neither System V init, daemontools, runit or perp provides any hooks to 
wait for a service to go up or down. runit provides a waiting mechanism, 
but it's based on polling, and the ./check script has to be manually 
written for every service." (https://skarnet.org/software/s6/why.html).

I know he's talking about Busybox's runit in this case, but would it be 
worth adding this facility to toybox?