I don't exactly remember the details as this was over 2 years ago, but as far as I can tell I copied most of the map KFMSNWDK from RS6 file, then fine tuned it based on log files.
I also remember that I had to add some really fine fine values around 0 to allow for better idle control, my first throttle plate values were 0.78, 1.18 and 1.57. Those I had to tune manually based on log files. This is because the difference in flow rate between 0.78 and 1.18 throttle opening was significant at idle RPM (I eventually managed to get stable idle at 800 RPM even with 1000cc injectors), but it would have probably been much easier to just raise the idle to 1000 RPM+.
I removed some of the higher values from the RS6 map to allow for this because my tiny 1.8 motor could never reach such high flow rates anyway.

Regarding WDKUGDN, once you have the values in kg/h, you need to use the KFMSNWDK to estimate the throttle opening at the calculated kg/h and RPM (hence KFMSNWDK is important to get right).

My advice (which is the advice given by prj at the beginning of this forum) is to use one of the VAG throttle bodies with well-known maps.
If you don't have access to a dyno, road tuning a custom throttle body is a very long and painful process unless you like the challenge and want to learn more about the inner working of the ECU. The problem is that once you get into adjusting throttle body/VE model etc (based on other mods too such as bigger MAF, different intake manifold, CAMS, injectors etc), you no longer have a fixed known variable, and as I found out, all these variables are so interlinked that you end up with a lot of guesswork.

I am not well equipped to give advice on Dyno tuning, since I do not have access to one.
I would guess that if you have a stock MAF (or a MAF that you are confident is linearized correctly in your tune), you can set constant throttle and RPM and for each point you can compare the msdk and mshfm and adjust KFMSNWDK so that the two match each other.

However, prj or someone else with extensive dyno experience and understanding of ME7 would be able to give much better advice than me.

To calibrate the throttle you don't need a dyno, you need a flow bench!
You must measure the maximum flow through the throttle at every throttle opening. PR is not too irrelevant for a throttle as long as it's > 1, but of course if you have higher PR, it's better.

Using a car and a dyno for that is well... dumb. And it's impossible to get all the data, especially for the smaller throttle openings, as the engine will stall.
It's the best to lift the data from an ECU where the throttle was used.