Found this Original thread about finding TDC and it was a great help.

Made a pic to better visualize the setup : the chopstick shouldn't be too short (plug hole is quite far away) and not too long (otherwise it will touch frame/accessories/cables). It is inserted to that it can touch the piston. The gum that forces it to male contact with piston must be short enougfh so that contact is maintained till the piston is down. The stickshoudn't come loose othetwise when up again it could settle in a different position and ruin measurements.
Did sandpaper the edge to have a nice reading gauge.

You are playing with quarter of a tenth of an inch moves at TDC, reason to note all readings from -10 to +10 degrees around what seems to be TDC. You'll see the indicator move down the gaugue as you reach tdc, then up again once you have passed tdc. You take two readings (before/after) that are the same and TDC should be in the middle. You wil see that it's perfectly symmetric.
More precisely to take the first occurence of a reading when going to tdc, and the last occurence of the same reading when going down from tdc.

My example :
From -4 to +4 : read 19.45mm on gauge ( to of curve is super flat, hard to see deviation with such a basic tool)
-6 and +6 : read 19.5mm
-10 and +10 : read 19.55mm

if you don't know where tdc is first follow chopstick move to find the "flat zone", then have a temporary mark on balancer and use the markings plate (goes from -10 to +16), then iterate. Of course it would be easier if you have an index on the balancer.

In my case that was easier as I wanted to check my balancer was OK, due to the strange timing (+14).
Finally the balancer was OK and car was actually at 14. Did put to 7 (usually works good between 6 and 8, did choose 7 so that I have space for 1 degree measurement error).

That did solve the serious idling problems (misses).