BMK2 used in cathode-biased amp

[Champ81]

I will going with the variation circuit where R(add) is in series with the stock 150R.

I'm testing out different R(add) for this circuit. The highest was 820R in series with the 150R. This produces a high DC voltage of 50V across the wiper and ground of the pot. I've tested different values and it seems that the higher R(add) increases the rate ratio turn on the pots. In post 6 you mentioned an Rk of 500R per tube. In this circuit would it just suffice to use a 100R R(add) in series with the 100R to make Rk 250R as a push pull. Since the pot max current is the same as stock I shouldn't matter how high the resistance?

Edit:
Please ignore the post above. The resistance value of r(add) sets the minimum current to the tubes via the pot. So a higher resistance allows you to bias it colder and increases the range.

These are the minimum values I measured with the variable eing R(add)
150R
Right side min 24.8mV
Left side min 23.4mC

510R
Right side min 13.1mV
Left side min 12.9V

820R
Right side min 9.4mV
Left side min 9.6mV

820R + 150R = 970R
Right side min 8.3mV
Left side min 8.7mV

820R + 300R = 1.12K
Right side 7.5mV
Left side 7.8mV

820R + 510R = 1.33K
Right side 6.4mV
Left side 7mV

The only other thing to consider I found were the capacitors on the wiper to ground of the pots. The voltage through goes up significantly to about 50plus volts so you would need to put in bigger caps. I think this would be a compromise between a larger range vs smaller sized caps on the pots.