Deactivate use of openCL at runtime
I suggest that DT offers a way to deactivate the use of openCL at runtime, e.g. as a configuration parameter.
Reason: GPU processing via OpenCL seems to be much more prone to a buggy system configuration than classical CPU processing. Defective GPU drivers, left-over libraries of an older install, or hardware problems can cause openCL to deliver bad results. I experienced this issue with an older graphics card (see ticket #8304). Switching to a new card solved the problem for me.
Especially if we think of binary-only packages switching openCL off might be the best option. Users get the output they need (somewhat slower though) and we prevent frustrating experiences with DT.