I’d rather not increase gamma, as it also increases how much (individual) bright pixel “grow” over dark pixel and I like it a bit reduced.
I’l try the parameter range increase as performance with my setup isn’t an issue right now 
This sounds interesting, not sure though if it fits my objective?
For me I’m after the glow effect as for a full black screen I don’t want any increase in black level (just like the test case: for full black screen, black luminance at 0.01 cd/m2 is practically zero.)
Only for increasing white/black checkerboard patterns the internal light reflections in the CRT glass lower contrast in the checkerboards, inceasingly so with increasing checkerboard NxN pattern.
Edit: which seems a purely glow related decrease in contrast as something bright must be nearby to create the internal reflections in the CRT glass.
You should also look it trough the perspective of other crt displays, crt display settings, shader target displays and their settings and of course there is also a reasonable implementation issue. IMO static glow looks too distracting if not tempered or used properly, while contrast settings, black level etc. are able to works more convincing. The problem really lies in the fact, that what you are after is a more or less a dynamic process which is at best hard to evaluate and static patterns are sortoff deceiving. But nevertheless it’s a good thing too look a couple of years ahead and also consider other display technologies like VA, QLED, OLED, AMOLED, even plasma. I’m an IPS fan atm. for the record. It’s a good reminder though, but it’s unlikely this shader will recieve a dynamic implementation.



