@acer Noted, thanks.

Thanks acer.  I've not had time to look at Maple again until now, but using OMP_NUM_THREADS gives me the way forward I think.  I can set it at 1 as a default, then if users want to use more threads, they will need to set it explicitly, which will force them to think about what they are doing.

I'm actually going to implement this via an environment module, rather than editing files in the Maple installation, but the effect should be the same.

Thanks for quick reply - I'll try that out.