> X5000 users with MorphOS got updated drivers for
> Radeons (R500-R700-), both 2d and 3D

...with the limitation that 3D support does not go beyond R500.

> and also frequency handling

What does this refer to?

> AGP machines have Radeon R400 max.

AGP graphics cards with x86 ROM go up to R700 but I don't know if they are supported by MorphOS on PowerMac G5 AGP.

> Hyperion [...] didn't provide drivers for Radeons
> in X5000 - Aeon did that.

AFAIK Hyperion provides a restricted (in terms of resolution, maybe also colour depth) driver with OS4 that enables at least OS installation. This driver is licensed from A-Eon or Hans de Ruiter.

> maybe just have two graphics cards in X5000?

This reportedly works with OS4/Linux (using a FirePro/FireMV card in PCIe x1 slot for Linux) but not with OS4/MorphOS. There was a dubious report of a Radeon R200 in a PCI slot working for MorphOS in the latter combination, though.

> 5-years-old AmigaOS4.1FE

FE Update 1 is 3 years old :-)

> OWB in MorphOS will be updated

Without engine update this will help only so much.