There is already a long thread about similar questions that you can find here: Dimensionally Inaccurate Parts Being Produced by X1C - #54 by jrovito
But in short: yes, a 0.25mm deviation on a 30-50mm part is an inaccuracy of 0.5-0.8%, which is as good as you will probably get on a consumer machine, especially one using FDM.
The best solution is to scale the models, by calculating a scaling offset for each material that you are printing. CNC Kitchen has a recent, comprehensive video on this that you can find in my earlier post in this thread.