#in-element Helper computing twice

I have an #in-element helper in list template.hbs. This list route consists of multiple nested routes. When i travel any of the nested routes. #in-element computing twice. is this common behaviour?

And is there any info about Ember’s rending pipeline?

Without more context I’m not totally sure but it sounds like you’re probably running to the in-element eager rendering behavior. In this article it says:

One thing to note though is that when the destination element changes, the content is re-rendered completely. For instance if your content has an input field and if you didn’t cache the value before the destination element changes, the value is completely gone. If you used ember-wormhole, the content does not get re-render but re-attached to the new destination element.

The in-element helper is a fairly low level built-in. If you find that it isn’t flexible enough I’d look at either ember-wormhole or ember-elsewhere addons.