Oh.. my bad. I misread your post asking for Linux installation.
Luminance HDR opted for Flatpak and if I'm not mistaken, Flatpak can be exported into USB or single file bundle. Refer: https://docs.flatpak.org/en/latest/single-file-bundles.html
Really depends on the developer doing for you
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However: sounds like you need an OpenWRT portable router with VPN configured (a.k.a shadow router). Even the bundle is available, the network shutdown still stops you from downloading anything.
