Unity Gain Tube Buffer - Choosing the Right Location

Hi Everyone -

I am about to receive and install a TVC passive in my system and have been considering purchasing a unity gain tube buffer. After a lot of research it seems that the combination of a TVC and unity gain buffer could really be a home run, combining the transparency of a passive with the attack of an active without any of the excess gain. I won't make any decisions before burning in the TVC but I just wanted to start thinking about this and it could be helpful for others.

My question is where in my system chain the buffer should be installed as this would determine which buffer I would buy and the connections it would need. A little system background - My digital chain is a Schiit Eitr > Metrum Acoustics Amethyst DAC > Promitheus TVC > Red Dragon s500 > Kef LS50. The metrum is single eneded and I will be using the TVC to convert to a balanced signal for the input of my power amp.

Should the buffer be placed before or after the TVC for the most sonic impact? I realize many people won't have explicit experience with this so maybe I am just interested in theory.

As far as I've surmised to this point - Observations of the buffer before the TVC:
-I could use the buffer to convert the single ended DAC signal to a balanced signal. The buffer would do the conversion instead of the TVC. I'm looking at units from Space Tech Labs which could do this and would be cheaper than a fully balanced design.
-The buffer would be running with a full signal voltage strength through it from the DAC (How will this affect s/n?)
-I will have an AVR feeding the TVC as well, I could bypass the buffer for home theater which is ideal.
-Unbalanced input to the buffer adds another set of RCA cables in the chain, which I understand have less noise rejection and more cable artifacts than balanced connections. Hopefully this will not outweigh the benefits of the buffer.

Observations of the buffer after the TVC:
-Constant output impedance to my power amp which will be lower than the source with any attenuation.
-The buffer will see an attenuated voltage signal from the TVC (How will this affect s/n?)
-I will have to use the buffer for my home theater if I don't want to keep changing cables (meh... struggles of integrated home theater and 2-channel)
-Balanced connections on both input and output (better I would think)

I've been searching online for some answers to this but there doesn't seem to be a lot of information out there. I wonder if the the buffer has more effect sonically after the TVC as there is a direct interaction between it and the power amp - I can see a lot of advantages to a constant and lower output impedance and fully balanced connections. This will make the buffer more expensive as I will need it to be fully balanced.

Any and all help/insight is appreciated!