Rare quests (Shrikewood, Farholme, etc for 4* ascension materials) occur mostly regularly more-or-less on Mondays.
The official line is that this is “random” , but this seems… unlikely given that Rare Quest timing so often “just happens” to slip most immediately preceding a Challenge Event, and official policy is apparently
Firstly, it would be easy enough to schedule Rare Quests so that they (A) don’t overlap Challenge Events at all or (B) overlap so minimally that it would not pose a problem for any player interested in both quests.
Secondly, it is disingenuous that having a Rare and a Challenge event at the same time is a problem. Maybe—maybe—back in 2017, with fewer events total (and fewer heroes to chase and ascend) it was, but more recently we get quest pileups like
and these are not the only instances, or even necessarily those with the biggest number of simultaneous quests.
Contrast, say, today (a Tuesday of a week during which there still hasn’t yet been a Rare quest, and all that’s running else is Valhalla Rising, which is… arguably not the most interesting of events nor critical for world-energy needs)
Not a whole lot to do here — and frankly it seems unlikely that this is purely random, given the above screenshot comes from a week immediately preceding a Challenge Event.
It’s time for this to stop.
Rare quests are a source of ascension materials that pretty much all players look forward to and need, as the only guaranteed earnable-in-game source of such materials
There is no reason that Rare quests couldn’t just spawn on an actually-regular schedule, regardless of other events (given that this is mostly what happens anyway)
The “restriction” against Rare quests vs Challenge quests is outmoded, unnecessary, and should be entirely dropped
(And finally, while I am aware there have been other, older threads calling for regular Rare quests  they are quite old but also  this request also specifically includes scrapping the ~6-year-old “no Rare quest if there’s a Challenge” excuse.)