According to the Ventoy web site IPFire works with it but I am not sure who has tested it and when as they have a list of 275 distros, the majority of which they have marked as “Ventoy test OK”.
There has been another post where someone has reported that when they used the ventoy app it always ended up with a kernel panic. They changed to Rufus and it worked.
https://community.ipfire.org/t/kernel-panic-on-attempted-install/9589/16?u=bonnietwin
It is reported that Ventoy works on the basis that the distro it is being used on either uses dm-mod or dm-crypt modules. Neither of these are enabled in IPFire. It needs these modules apparently because it injects some code into the boot process.
I don’t understand the details but the sound of “injecting some code into the boot process” does not make me want to use it on a firewall distro.
It was apparently tested with Core Update 144 on a QEMU KVM.
At that time the dm-mod and dm-crypt kernel modules did not even exist in IPFire so clearly at that time the ventoy app used a different methodology than it does now.