A bit OT but anyway, remember that years and years ago Hyperion originally stated that the classics would only get 4.0. So it's a bit late to get upset about that should not 4.1 for classic come to pass.
Could you please consider of making use of hardware trick to use the mediator pci bus board ? i know that you wish to have a clear code, but you still can have it as there is the amiga one version.. I think that the classic os4 version should encounter some measure to fully use all the potential that the Mediator Bus Board can give to classic hardware.. And please consider that the Mediator is maybe the most selling hardware for the classic model in the amiga market in the last 5 years..
I think Hyperion basically just supported Voodoo on Mediator than Mediator itself as this is a common gfx solution among classic PPC users. 8129 network too. Both of these do not require the buffer trick, so , basically - I think - Hyperion just supported the most basic things a Mediator can have without buffer tricks. Writing proper drivers for mediator itself for OS4 I believe is something Elbox should do, it's their device. Of course the 68k drivers can be run emulated under OS4, but it's not really a great option - ie many slow downs and crashes.
would you at least consider making a last cairo-less version of OWB with working downloads and , maybe , bookmarks?
No, besides the double work for maintaining 2 different versions just building one OWB executable takes several hours.
OWB 2.9 doesn't use any new AmigaOS 4.1 features, all I need for an AmigaOS 4.0 version is an up to date Cairo port for it, the one on os4depot.net is too old. I don't have the time dto do it myself, but AFAIK Cairo can be build without any changes in the sources and if someone else builds a current verision of Cairo I'll build AmigaOS 4.0 executables of OWB 2.9 and newer versions with it.