Need help optimizing my Fluent Meshing Workflow
 

Hello,
first off my background: I'm taking part in a student run team that designs, builds, tests and races a small single seater formula car. This competition is known as FSAE in america and as Formula Student in europe for anyone that wants to look it up. For this I'm responsible for simulating the aerodynamic package using Ansys Fluent 2019R3 which Ansys provides to us as part of a sponsorship deal.
Now because we are all students and not formally trained this question may be simple to you but I couldn't find an answer to it yet.
We have many different design iterations of the aerodynamic package, some with quite large geometric differences (added flaps, different number of wing elements, etc.).
Now I want to run as many simulations as possible and for that I want to automate certain aspects of the workflow. The Setup of the boundary conditions for example is easily transferred from case to case. For the transfer of the boundary conditions to work I import the geometry as a STEP file into spaceclaim and prepare it as well as create named selections/groups which always bear the same name. (e.g. the component for a group of two BOI's used for the wings is always called BOI_FW_RW, or the face of the radiator is always called Rad_Face)
We built one "template" first and then saved copies of the Workbench file using the save as feature. Each of these copies represents one design iteration. Sometimes the zone names change for no reason after mehsing (e.g. Rad_Wall:123 turns into Rad_Wall:124) I also can't figure out why that happens, but that isn't too bad since it is easily fixed by a match zone names operation combined with a reload but if anyone has a solution for that it would also be greatly appreciated.
Now the main part: Within fluent meshing I first import the spaceclaim file, then I define the parameters of the surface mesh (curvatures, BOI's, proximities, ...) using the scoped sizing tool. After that I remesh my domain using the individually option. Then I check the surface mesh using the summary tool, this almost always shows a large number of free faces, multi faces etc. I got these numbers as far down as I could in the construction of the CAD model. At this point I usually export a size field and re-import the geometry using that size field. After that there are usually only about 20 skewed faces left and that's it , no free faces multi faces, ... whatsoever. These can be easily fixed using the diagnostic tool with the overall improve option. After that I calculate the volumes and start the Volume meshing process using the Auto mesh tool in which I specify my desired number of prism layers, first cell height, etc. I then mesh my geometry using the Poly-Hexcore mesh in parallel mode which pretty much always works except for rare instances where fluent divides the geometry for meshing in some weird way onto the 12 cores (I guess that's the reason) and fluent just crashes in the meshing progress. This is usually fixed by lowering the number of used CPU cores by 1.
Now I want to ask if it is possible in some way to speed up this process? I have tried using the same size field file on import for different geometries but this leaves newly introduced geometry elements in a very badly meshed state even though the are part of a previously existing named selection. It also results in what seems to be mesh parts of the geometry that was first used to create the size field file showing up in all other geometries that are imported using this file. (E.g. Smaller mesh elements from where a geometry used to end showing on the now extended geometry with the extended part being badly meshed and not using for example Proximity conditions)
I would very much appreciate some help in this case.
I also apologize for any grammatical or spelling errors or communication mistakes as I'm not a native speaker.
I'm looking forward to your answers.
Thank you very much!