I like that idea of yours very much.

My FC didn't like my ideas very much.

1, Having such buffs will not represent the real fight and can't be good practice since the phases will be phase out.

2. Practice only phases will not guaranty players have cleared all the phases for the real clear.

Here is a third idea :

What i wish is SE to implement some tools so i can recruit players that are on same progression as i am.

Here is the tool : In PF, it can show, next to your name, the % of HP left from boss... Your best stat. You could easely ask "players under 30% only". Not a perfect tool, it has it's flaws, but it helps. Like if someone had paid for a clear, didn't get the wep, and now wants to try again...

I am just super tired of going back in PF, precisely because people lie and pretend to be on a progression they are not. That, right there, is a HUGE time sink and super annoying. Makes me want to only try these in a static.