Mixed media experiment with oil paints

On Sunday I finally added the next layer on a canvas I had first been working on in August last year.
Back in summer 2021, I tried to explore one of Jesus' most intriguing comments about the spiritual life (“The wind blows wherever it pleases”) in oil. I incorporated feathers and seeds to create a sense of texture and movement. (You can read my initial blogpost here).
However, the feathers clumped, and the seeds did not stick properly. When I researched the use of collage with oil paints, I discovered that oil paints are likely to react with collage materials. Oil paints also have very different properties from acrylic paints (acrylics are essentially pigmented glues).
Some people suggested alkyd paints as an alternative to oil paints for mixed media pieces. However, alkyd paints are not environment friendly. I also wanted to use materials I already had rather than investing in yet more paints.
I added some charcoal marks to the canvas to express a sense of unpredictable movement, but knew they would not last either, unless I used some fixative, which are generally not environment-friendly either.
As I could not figure out how to continue with my project, I abandoned my canvas. This is where I got to:

However, in recent months I have been learning about egg tempera. I have read that egg tempera was in the past used as a base layer under oil paints and that egg white is a strong glue - it was even used as a mortar in early church buildings!
Can egg tempera work on top of oil? Will collage material stick to oil with the help of egg white? I decided to find out: I mixed egg yolk and egg white with Brusho crystals and seeds and poured the two mixtures onto the canvas. This process has created some exciting textures and layers.

I am not sure how the different materials will react over time, so I am taking high resolution photographs every step of the way so that I can create Giclée art prints.