Now applying the patches has worked. I simply had a double patch with two different numbers in the title. Once I removed one of them, it worked without any problems.
Now, however, I'm having problems with ./configure; I get this result:

./configure --prefix=/usr --with-single-user --with-config-dir=/home/paz/.bcast6 --enable-libsvtav1 --with-vulkan
[...]
configure: error: Please install autoconf-archive package and re-run autoreconf

After installing autoconf-archive, ./configure worked normally. What is autoconf-archive used for?

The “YUVA-16 Bit” color model applies without errors and playback works, but none of the native filters in the “Color Correction” section work. The error message is:

VFrame::to_texture: unsupported color model 16.

(Note: Using the compositor's videoscope works fine; using the videoscope filter on the timeline does not work.)

Regarding rendering presets with Vulkan:

When I use your preset (ffv1_vulkan.mov, with pix_fmt=nv12), I get this error:

cant find codec ffv1_vulkan:/home/paz/test_vulkan.mov
Render::render_single: Session finished.

If I use one of my presets (e.g., hevc_vulkan.mov). I get:

Specified pixel format nv12 is not supported by the hevc_vulkan encoder.

Even if I change the value nv12 --> vulkan, rendering fails with the same error I've always had and can't resolve:

A hardware frames reference is required to associate the encoding device.

I have never been able to understand my problems with Vulkan, which are beyond my capabilities, so there is no point in continuing to try. Sorry.