Why wouldn't this be done for each HFA release? As the steward of the source code, we're reliant on Check Point to provide the latest images unless Check Point provides a tool to custom bake the HFA's into a deployable image. I'm not expecting Check Point to provide images for all patches, but I AM expecting to see images for each "Recommended" HFA.
And, from my lab, here are the **bleep** image sizes, the First being the image directly from Check Point, the second R81.20 Gateway only, not you managed by the multi-domain manager, all I did was update to the latest HFA (Take 41)
-rw-r----- 1 root kvm 4589092864 Jan 4 21:12 CheckPointR81-20-GW.qcow2
-rw-r----- 1 root kvm 15321792512 Jan 8 14:35 ncflabcpfw0002.qcow2