You don't need a vu buffer amp. API consoles did not have vu buffer amps, and neither did most consoles pre 1980, and at least half of 1980 to 1985 consoles still had no vu buffer amps.
A true vu meter will read 0vu when driven by a +4db signal through a 3.6kohm resistor. The 3.6kohm resistor buffers the signal just enough that few will notice the tiny added distortion and actually distortion from a vu meter fed by 3.6kohm resistor makes for better sound for all forms of rock and pop music but probably not legit traditional classical or jazz. It may be that the improvement in sound will only happen if the signal path is Output tyranny>>3.6kohm resistor>>vu meter. Historically the move away from true vu meters to toy meters driven by buffer (beginning around 1980) probably contributed to the apparent thinning sound (as compared to vintage gear) but it was often experienced cuz a lot of vintage consoles built correctly were still in use. As the SSL and Neve V series pushed a lot of or most of the vintage consoles out of top rated studios the sound of pop and rock music thinned out across the board and yet there were still some fat sounding recordings for various reasons such as tracked at a "B" studio that had a vintage console even though mixed at an "A" studio on SSL console.
Even though with some difficulty one can find cheap (made in china) vu meters that require the 3.6kohm resistor they may still be toys in that they will not have correct ballistics...typically the needle response will be too fast, and so distortion signature might not be the right flavor.
I'm just guessing...but if you look at this recording session (look at the gear, use of protocols) I suspect a lack of vu meter distortion....so sad in a way...japanese rockers wowed by Ed Sheeran's succe$$ (even though different genre) and they ended up with a sound of only average excitement and only faux angst compared to, from similar genre, "In the End" by Linkin' Park.
"In the end" was recorded at NRG studios in North Hollywood, Ca, circa 2000. I think they had a Neve console.