"buildsystem": "simple" for a Python Flatpak

I like the simplicity of Flatpak manifests, it seems streets ahead of other formats which require several files of different sorts. This question is about making things even simpler. I have a Flatpak which contains several dependencies which are compiled from C, then this to install the main Python program:

  • name: myapp
    buildsystem: meson
    sources:
    type: git
    tag: V1.1.1
    url: blah

This uses Meson which has a meson.build file which finds appropriate directory names and does things like this:

bindir = get_option(‘bindir’)
datadir = get_option(‘datadir’)
pkgdatadir = join_paths(get_option(‘prefix’), get_option(‘datadir’), ‘myapp’)
conf = configuration_data()
conf.set(‘pkgdatadir’, pkgdatadir)
install_data(file, install_dir: pkgdatadir)

Alternatively there is “buildsystem”: “simple”, like this (this example is for a Bash file not a Python program):

    {
        "name": "hello",
        "buildsystem": "simple",
        "build-commands": [
            "install -D hello.sh /app/bin/hello.sh"
        ],
        "sources": [
            {
                "type": "file",
                "path": "hello.sh"
            }
        ]
    }

Can I install Python program in the module in the manifest as in the above example, by using “install” plus other Bash commands, without the extra complication of using Meson?
I’m assuming that there is nothing magic about installation, all that’s needed is to discover the correct directories, then copy the files to those destination.