There are multiple points in canon where Dick was isolated from most of the batfam members, I think this is the prefect opportunity for older sibling lore drops.
Have Dick causally mention that he was Batman when Bane broke Bruce back (when Dick was only 14).
Have everything with the court of owls happen when Bruce is lost in time (so only Afred, Damian and Steph know) or during early Jason as Robin days (so only Jason, Bruce and Alfred know).
Only the Original Titans know about Dick time as Renegade.
Killing the joker? Only Tim, Bruce and Alfred know.
The lore drops would be iconic.
Tim: Damian you should talk to Cass, I’m sure she would understand what it’s like being raised as a weapon and being trained by assassins.
Damian: Drake why would I talk to Cass when I can speak to Richard.
Jason: What are you talking about Dickface was never trained by assassins.
Tim: Dick!
Dick (coming into the batcave): Yeah what’s up guys.
Jason: Demon brat here seems to think you were trained by assassins.
Dick: He’s right. Which time were you talking about.
Tim: What.
Jason: I’m sorry which time?
Dick: Technically I was raised since birth to be an assassin for the court of owls. But my training was pretty light. Mostly acrobatics, learning languages, throwing knives, lock picking, escaping bindings, contortion, endurance… you know basic skills anyone would learn growing up at a circus. I guess the plan was for training proper to start when I was 16. But you know Bruce ended up taking me in. Through funnily enough when I was around 16 Slade Wilson infected the Teen Titans with nano boys that would kill them if I didn’t do what he said. He trained me for a few weeks, made me steal a few things for him and fight my team. Obviously I escaped. The Court of owls came back for me couple years ago when Bruce was lost in time. They tried to turn me into an undead assassin. It didn’t take. Steph and Damian got me out pretty quick.
Tim:
Jason:
Damian: You act like this is new knowledge.
Dick (shrugs): Want to have some lunch Dami?
(Yes I’m smashing together canons, and messing with the timeline)