It's well worth a try, CREATIVE. Whatcha got to lose by trying? When I wanted to make faux Van Gogh, I painted the back of textured clear glass. When I cut the sheet of glass there were a few chips around the edges, but most of them were covered by the mortar and grout.

This isd a repeat post. Sorry.

Sorry I have no clue what you want to do. Why decoupage at all? The cabinet is quite nice so I have no idea why you would want to ruin it

I have dried and pressed flower for years as a gardener and artist. Pressed flowers are nice for things like greeting cards but their color fades over time. The stenciling for texture with joint compound would last longer but could be sanded on or floated over when ready for a change. I do a lot of ceramics with texture from botanicals The concrete on my pottery shed has fig leaves prints. So you could experiment with using leaves or flowers to imprint texture in joint compound spread on cardboard. You can mix cornstarch and silicone sealant to make molds/stamps of flowers so you don't need a bushel of leaves. Experiment before starting on walls.