Dedicated Vinyl system next upgrade?

Your system seems top notch. Top end brightness can be somewhat resolved with speaker placement and room treatments in my opinion. It’s the “ghost” in my system as well. I’m in a similar place with my system. Totally satisfied 90% of the time. The only upgrade I have done recently was to send some of my reference Lps out for a proper cleaning. I used www.thevinylarchivist.com as he is local to me. I can’t tell you what an improvement a proper ultrasonic cleaning has done for the LP’s I had done. It’s insane what a difference it has made. Even on seemingly “perfect” pressings I own. Good luck on your journey!

Side 2 I believe in You is obnoxiously bright and forward. I hate to say this as there are lots of super songs on this disc.... but this might not be a touchstone reference disc ( certainly in its entirety) I hate saying that. Harvest is so much more balanced imo.

What to upgrade is the question.

The upgrade Itch.. 
I am thinking like this.. You have a stereo setup in a room. Changing/upgrading a component here or there gives you maybe a better sound or different. Give or take some % in improved sound quality. 

Your room is a component that is not coincided that much and now we are talking about much bigger improvements to gain. Some say 30% to 50% of the system sound quality is from the component "room"..

So if you  are seriously searching for better sound quality start with the bigest component the room.

Every dedicated listening room that I have measured has issues. Period. And nobody can as a measuring system say "Oh I hear a peek at 73 hz of 27 dB" yes nobody knows that before but with measuring we know. (Measuring is knowing)

So do not go into that rabbit hole that is a lifelong swapping out component X and Y and repeat. Into the same and lousy sounding room. (Remember you do not know how bad it is when you haven't measured it)

When you measure and fix your room THEN it is the first time you truly hear your gear and get full return of your investment!

So what to buy? Then I suggest a calibrated measurement microphone less than 100$ and install free software REW. Invest time to learn how to measure and how and what room treatment does and so on. Learn where your listening space issues are. And deal with them.

This is the hard way to go, to force you to learn new things. It is SO much easier to swap a cord or place some vibration damper here or there. And most of us do that our whole life because we are lacy. But we will also never fully be able to hear our components full capability.

(As a side note when we have done what we think is a appropriate level of room treatment then it is time to look at DSP/Dirac and those type of "room corrections". 
I love my vinyl system but analog purists do not know what they talk about. They have a obsession that it should be 100% analog all the way. I have done exactly that journey.
We have so much more to gain in % of sound quality than the small loss of sound quality we get from converting to digital and do sound processing and then convert back to analog! 
Just that type of thinking is holding many audiophiles back from hearing better sound quality from their all analog setups! Again we are lacy and have come up with a false logical conclusion "all analog regime" and then we do not need to learn new stuff like room acoustics..)

You can get to a great RT 60 without DSP, go there first :-)