I agree. 10char.I say you keep it all.
Hal going crazy. Bruce being an emotionally abusive control freak. Diana killing Max Lord. Clark killing all the people he's killed. Arthur and Mera's various break-ups and Arthur's various periods of broody depression.
You keep it all, and you make it work for you.
Fans aren't going to forget. Even if DC pretends that (for example) Zatanna never mind-wiped Batman, that's going to be in the back of our minds and it will impact and influence how we see Zee, no matter what DC says "really" happened. So instead of ignoring it, make it work for you. Mistakes and flaws are the fertilizer that great characters grow (and continue to grow) from.
I'd rather have Zee say "I hate that I did this to Bruce, and I have learned about myself and grown as a person and won't make that mistake again!" than say "Mindwipe Bruce? Why, I'd never do that! What would give you such a crazy notion?" and have DC tell me that various stories happened in a different way than they actually did.
If you're going to change your stories around and pretend they didn't happen the way you wrote them and you won't use those to build from, then what's the point of continuity in the first place?