Well, GOG aren't game developers and they don't usually have any access to the source code of the games they sell. They are, after all, only a distributor. So a true fix won't be possible, but unofficial community patches have been utilised in getting other games to run and then be sold here on GOG, so it may be that the only solution would be for them to include some kind of CPU limiter (if it is indeed related to CPU cycles) or provide the DCOTE (or a modified DCOTE) patch to allow users to make use of it if they need it.
I'm currently waiting to see if and how this progresses before I decide whether or not to buy, though it is already far better than the Steam release from what I've read, and it may be the best version available for today's PCs.
EDIT: In fact, can anyone see if DCOTE is already present? Only I just saw a post saying that there is a CoCDCoTELauncher.exe inside the engine folder in the game installation (used to change the screen resolution).
If GoG decide to sell a game then the game has to work, it can't work up until a point and then not work because that is selling a broken product and that in most countries is illegal.
I did look in the engine options and did find a CoCDCoTE launcher but that is literally just the options menu, which allows you to change resolution and the usual stuff, sadly no way to change the movement.
Also I did hear a long time ago there is a 3rd party patch to increase the timer for the tunnels, I've no idea why it was not used since it was a common bug. They did say they used other patches to fix some of the issues.
What I can't stand is the lack of communication since I know there has been a dev in other threads talking to people, why they will not talk to us here I've no idea.