Hewlett-Packard has never heard of a rent they didn't want to seek, so iLO definitely has bullshit extra fees for remote management after the firmware exits.
HP also unlike Dell requires a maintenance contract to get the latest ilo updates. The free ones are years behind, so if there are zero days for ilos then many price-sensitive users purchasing them on the secondary market are vulnerable.
Dell iDrac requires the enterprise license to get KVM-over-IP.
> Who else provides licenses for features?
Every enterprise grade hardware provider as far as I am aware.