I know from discussions on the DCP-o-matic mailing list that this has been in the works for several years, but it's not at all easy to implement. There is no open source DCP software which can do GPU-accelerated rendering. This is the main feature which makes the paid-for software options advantageous.

So I think it's a bit unfair to say it "should be" implemented. That is asking a huge amount of work on an endeavour that many have tried and none have yet succeeded in the open source world.

Please see https://dcpomatic.com/mantis/view.php?id=328

Hey overlookmotel,
Thanks for addressing this...btw, I wasn't intending the request as an "unfair" intention or ill-will gesture. So, I do apologize if that's how it was perceived. ;)
I didn't think it was an easy request by any means, but a very beneficial one, that's all. Also, I wasn't sure if there was a preference I was overlooking to assign some of the grunt to a gpu(s).

It's great having an open source solution at all. I just saw there was a place for feature requests and so I submitted a feature request. :)

Ah, sorry I took you the wrong way. Just, as a maintainer of open source software myself, I've sadly got used to unreasonable "I want this, you must do it now"-type requests, so have a bit of a sensitivity on this.

Yes, it'd be very beneficial to offload work to GPUs, but it seems to be very hard to achieve. So I wouldn't expect this any time soon. But hye, one day...