Well there is. One. Major. Above 10 slots you can still get a random purple trash badge. Equivalents of ‘equip most’ method are ‘equip above-Blue badges’ or ‘don’t raise useless (for you) heroes past Blue(+0)’.
All delete the trash badge chance. ‘Equip all’ method does not.
Ok back to my original question above. Numi failed to answer. How do your badges need to look like in order to go below 10 possible drop choices without failure chance. Be more specific, I want to learn the secret 
idk, I have all my badges equipped. I find it much easier to manage and I’m not sure I’ve ever got a random badge as long as I’m above the empty slots cap.
I believe he means that you need 5 badges equipped with the 6th badge crafted but not equipped, so a green plus 
That is exactly what I’m challenging. I still think it doesn’t affect the badge crates rules at all. So I’m waiting for someone to provide solid evidence. You comment made me think you’ve successfully gone below 10 without fail chance, apologies for that.
I have a lot of heroes on which I keep 1-2 badges non-equipped just so that I can use them to get the PW heroes faster to Yellow. Those slots have never to this day affected the 10-open-slots rule for me.
Well you won’t get a trash purple badge if you have above 10 open slots and have fully equipped all other heroes. Would you care to explain what you mean?
This is not true. It tends to go this direction, but isn’t certain. With 5 equipped and last one with a green plus and “EQUIP” below and the badge in question being crafted for each hero (so, multiples)… the chance isn’t there.
Again - that it doesn’t happen to you does not mean the chance is not there. That’s like with climate change discussions, with the deniers.
Sad truth - this cannot be mitigated. Even if the last 10 badges are the last Y20 badges possible to get with badge crates - the fallback will be there. @Loutre the badge crate in this regard is very vaguely programmed. Which is odd since the coding is pretty exact and specified.
I give up, you win 