Biggest impact: moving from integrated to separates

I know you're looking for separates but consider this integrated.

https://www.audiogon.com/listings/solid-state-plinius-hautonga-integrated-stereo-amplifier-remote-10...

If you haven't heard one you'll be amazed. A buddy of mine  uses one and you would never know he doesn't have separates. This would also allow you to have some funds left over for other upgrades. Just throwing out possibilities.

My personal experience...
About ten years ago I bought a used Pass X-1 pre-amp. It replaced a Linn Kudos.
The change was transformational!

Soundstage, air, so uncongested....
it was like I'd been listening to music through a megaphone.

So if it was me, I would spend the money on a  line stage...

I’m a big fan of the Mytek Brooklyn. Balanced outs to my Bryston 14B ST. Very good sound and versatile. I run it off an RV battery and it's very quiet.

I also found that my last few preamps were the bottleneck. I bought a c-j Classic 2SE and it was a huge improvement . I have used it with several amps and they all sounded better with it driving them.

I don’t know how much power you would need but sometimes a nice tube pre and a decent SS amp are a good choice.

If you have efficient speakers and 40 watts will do, Quicksilvers Mid Mono amps and Line level preamp are under 3k and are great. I own the amps and love them. Are they better than your Rogue? Hard to say because they make really good equipment too. So what ever you narrow it down to, if you can audition that’s going to save you some disappointment .  I've had some well respected gear on demo and it just didn't gel in my system.