Since I don’t currently have any important work to do while at work…
Inkscape. Newer versions have a MSI file. Should be very easy to make a Snapin with.
Download link: https://inkscape.org/en/gallery/item/11263/inkscape-0.92.2-x64.msi
LanSchool. No idea what this is, but it does offer silent installation options so you should be able to script something.
https://helpdesk.stone-ware.com/portal/kb/articles/install-uninstall-lanschool-via-the-command-line-cmd
https://helpdesk.stone-ware.com/portal/kb/articles/scripting-or-mass-deploy-switches-for-lanschool-install
Scratch 1.4. Use the msi file available here. It has an ini file with it, so upload the entire zip file as a SnapinPack and choose the msi template.
http://download.scratch.mit.edu/Scratch1.4.msi.installer.zip
Scratch 2. Already showed you that one, but there are newer versions available.
https://scratch.mit.edu/download