Only as we sometimes run into that while annotating models. Could there be terms like "dilution of entities" in SBO or does that not make any sense and should we just use "degradation" or generally "process"? If it makes sense, it could be directly under "process". Also some rate laws for dilution of species and growth might be interesting - something like exponential, Monod and logistic growth, if I run into any in a model I will send them to you ;) For dilution maybe just normal in/outflow or dilution by growth, I think we have those in some models already.
All the best