Deinterlacing & "Threshold" Questions

[WeBeDazzling]

Regarding deinterlacing.  When using, for example, "dgbob" or "Kernel Deint.", the value input for "threshold", is a lower value more precise, or better, than a higher value?  More specifically, is a higher or lower threshold value going to give better results? 

Same question for different filters.  "Threshold" in other fields, for example, "Luma Stabilizer" (reduce flickering)... for optimal results should a lower or higher threshold value be used?  Generally speaking, I'm sure there are anomalies or outliers depending on the video being edited.   

Lastly, does anyone have any recommendation(s) for best deinterlacer available on avidemux?

Thanks for reading & thanks in advance for any feedback.   
WbD 

[eumagga0x2a]

Lastly, does anyone have any recommendation(s) for best deinterlacer available on avidemux?

VDPAU in frame-for-field mode (doubling the frame rate) on Linux with NVIDIA graphics card and proprietary drivers.

On all other operating systems, never used for processing anything other than Yadif.

[alexstorm]

I don't bother deinterlacing much, because I do not use interlaced media.

For Mp4 you could use Libavedec Deinterlacers.  I would try also Decomb Telecide with No Strategy unless you also have 3:2 pulldown.  The default settings are pretty good.
Field order: top
None but compute
Never
7.00
50.00
10.00
50.00
Turn blend on.

Some things to consider:  Interlaced 640 x 480 is recorded with 0.9 rectangular pixel size.  So you need to pull out the interlace before resizing the height to the correct 4:3.  Ideally, you take the original 640 x 432 and remove the interlace then resize to 640 x 480, not the other way around.  The most important part is using the blend to soften the edges.

Better solution would be to see if the original media is available in a non-interlaced copy.

Hope that helps.

[WeBeDazzling]

Thank you @alexstorm!   Same, I don't use deinterlace but when I was playing around with it on a video, for eg., this one, 
deinterlace example

   ....there seemed to be better upscale results when I tinkered with deinterlace.  Yet all the various deinterlace options are a bit much to the layperson.   

* "Threshold", does a lower threshold or higher threshold value, when time is not an issue, create more optimal results?   

Thanks for the tips @alexstorm