Hi Gabe,
Thanks for clarifying your intentions.
Basically every memory timing must be configured according to the datasheet of the memory device.
Then the IP can be generated for the device.
If everything is configured correctly, the memory device should be working.
If the device is using the different memory timings, your design might encounter some errors such as timing violations or calibration error.
So I think generating each IP for your memory devices should be the best way to simulate your project.
I don't think that re-adjust the memory timings internally is a good way because you might be setting the value wrongly.
Regards,
Adzim