I'm pushing for E6, and I'm having trouble doing this in my current org. I'm considering an org switch, and I want to make sure I don't end up in a similar situation - How can I properly evaluate an org for availability of scope and mentorship?
Ask teams what they've shipped in the past 1-2 years. If there's a lot of launches, great. If there's not a lot, that's a troubling sign. You don't need to take their word for it either - You can go through experiment/ship posts and see what they're actually landing.
Look for a "medium" developed team where there's an initial product with some core metrics, but there's still a lot of room for improvement. 0 to 1 orgs can be frustrating to make a case for E6 in as goal metrics aren't clear and the org is very chaotic, while extremely mature orgs can be frustrating as the goal metric is clear but it's impossible to move the needle - The existing product is optimized to the teeth.
For working through others:
Make sure that whatever team you join has other E5s and some E4s.
Find a team that's more collaborative and warm as opposed to one where everyone is more competitive/a collection of lone wolves.
Look for mentorship culture. If there are engineers seriously mentoring other engineers (i.e. they have recurring 1:1s and help write growth plans), that's a good sign that the E4s/E5s on the team are willing to be mentored by you.