OK, for the record and for the benefit of the original poster, I will go out
on a limb and say the "important," "omnifilter capable" feature was a joke.
Most of us know that, but the original poster apparently did not, since his
response was to thank the poster and then say "will look into this...."

Hope I didn't spoil anyone's fun by saying that. Just didn't want to confuse
the OP any more than he apparently is.

You misunderstood what I meant, which was briefly stated.
All an in-camera (or playing with raw files) system can do
is apply
two numbers as a correction: the ratio of the gains of the
red and green channels is one number, the ration of the blue
and green channels is another number. As you say the white
balance settings can set these two numbers any why it wants
to, and you can set them any way you want to using the data
in a raw file.

But with only those two numbers, there is one critical thing
niether you nor the camera can do: correct the ratio of
sensitivities inside the bandpass of any one of the three
color channels on the Bayer filter. In other words, consider
just the blue channel. At 6000 K the ratio of energy at 480
nm to that at 410 nm will be lower than that at 2800K. The
two-number correction system can't fix that difference. A
filter in front of the lens can.

Doug McDonald

Doing Interiors  the Problem is the correction you make later WILL
affect the tonal range-perhaps adversely, and its a lot better and
quicker to add a filter on camera & then check my filtration on my
laptop screen.

Than to get back home only to realize the camera was set incorrectly
and have nothing to reference. When you are trying to precisely color
match something quickly-yet accurately nothing beats being able to check
the original scene and nothing is faster than balancing using a filter.

White balance in post-production, and in-camera for almost all cameras,
is simply adjusting the relative levels of the color channels.  If you
shoot, for example, under incandescent light, the white balance needs
to boost the blue channel by a large amount; this results in also
boosting the noise in the blue channel, and increasing posterization.

If you use a correction filter, the light is balanced prior to exposure
and this doesn't happen.  This can result in somewhat higher quality,
if you can afford to take the time to put on the filter and you can
deal with the light loss from it.

If you want to get really serious about that, the idea is to balance
the light to the camera's idea of neutral, which is fairly well into
the realm of magenta.  A magenta filter under daylight can, evidently
(I haven't tried it, myself), decrease shadow noise and posterization
by avoiding the digital white balancing.