Can axis be inverted in "gmt subplot"?

Hi GMT,
I know I can set -J like -JX3c/-2c to set y-axis inverted. But in gmt subplot, I have to set width/height in both -Fs and -J with zero height in -Fs . For example,

gmt begin testF png 
    gmt subplot begin 2x2 -Fs3c/0c -A -R0/10/0/10 -JX3c/-2c
        gmt subplot set 0 
        gmt basemap -Baf
        gmt subplot set 1 
        gmt basemap -Baf
        gmt subplot set 2 
        gmt basemap -Baf
        gmt subplot set 3 
        gmt basemap -Baf
    gmt subplot end
gmt end

output will be

what if I use -F instead of -Fs? Since I want gmt to compute each subplot dimension,with y-axis inverted. What should I do?

Thanks!!

It’s certainly possible but I would have to output the generated GMT command to see what I did

See first example in
https://www.generic-mapping-tools.org/GMTjl_doc/documentation/modules/subplot/index.html#subplot