I have a colleague who insists that she can't use kdenlive because pixelation of faces is to complicated. (We do need this quite a lot.) She is used to the process of DaVinci Resolve on Windows and I can't get her to use the truly free kdenlive. (This is especially annoying because DaVincis most recent GNU/Linux version has several serious issues like limited video format support and that sound does work only in the non-free pro edition with a specific Blackmagix sound card. The logical conclusion is that in the end we would need to set her up an expensive Windows system even if we want her to use a free operating system with kdenlive instead.)

Unfortunately the auto-tracking in kdenlive does only work in very specific cases with uniform background. At the moment kdenlive only allows to define static areas for pixelation if it needs to be done by hand. Each time the object to be be masked leaves the static area you need to cut the clip and adjust the placement, size and shape of the pixelation box. This can become daunting if you need to anonymize several persons in a video with a lot of movement. And a circle or oval would be better for this kind of task also.

From my perspective it doesn't look like it would be unreasonable hard to add a feature that enables kdenlive to make use of vector shapes as filter masks that can be animated independent from video tracks. Unfortunately I'm not a programmer and I am new to kdenlive too. But I would love to sponsor the development of such a feature for kdenlive ... at least if I can afford it.

So, how can I find someone who might be capable and willing to take on such a project? And would the kdenlive community even welcome such a functionality?

Sorry about the dissapointing reply but I am just a average kdenlive user who can't directly help you. However a little suggestion can't be harmful, right?

From what I have heard the "Motion Tracker effect" from the "Misc" section seems to track objects much better than the auto-mask effect. I know, it is a small suggestion that won't help much but I gave my reasonable best.