No. First there is IIRC warning in either the owners manual or the factory manual about installing any screen in the radiator openings. ('course, that is probably going to be (mis)interpreted by some owners that it is OK to do this as the belief of some owners is Porsche doesn't know squat about anything.)
Sure some will point out that some newer Porsche models come with mesh. But I would expect the car's aerodynamics to take what the negative affect the mesh has on area size and air flow and compensate for that. IOWs, I would no more remove the mesh from a car that came with it present than I would add mesh to a car that didn't come with it originally.
Ignoring the faotory's guideline on this subject, there are several problems with adding mesh.
The mesh reduces the area of the opening. Depending upon the wire size and spacing the area can be reduced by 15% to 54%. I have a chart somewhere that gives the mesh design, block opening in inches, the wire diameter in 1/16th's of inch, the open area in %, and the reduction in % from the total area. A fine enough mesh to filter out some stuff would probably tends towards the upper end of that area reduction number.
Another problem is the mesh would instead of letting a large piece of plastic or paper go through/into the opening the plastic/paper would instead plaster itself across the mesh and block some, most or possibly even all air flow through that radiator duct. Once in a while I spot an oncoming car with sometimes a rather large piece of paper or a plastic shopping bag plastered across the front the radiator grill work so this is not an uncommon thing.
While I have found that both of my cars can keep their cool with one radiator fan non-operational I have never experienced a situation in which air flow through one radiator was mostly to completely blocked and I don't want to.
Even with the mesh one doesn't get excused from having to keep the ducts cleaned out. The radiator duct would still have to be periodically cleaned out. The mesh doesn't keep the finer stuff out which will still accumulate and without the fluffier stuff -- leaves and such -- compact to a much denser and harder material -- think baked mud -- which would be much harder to clean out and remove. I would not want to have to go at this stuff with a screw driver or any sharp object to break it up and remove it.
It is not hard to clean the ducts out. If one keeps up on the accumulation of trash every so often a blast of air from an air nozzle from the right places from under the car will blow the stuff out. I have this done every time I have my cars in for an oil/filter service. Based on my usage this occurs at least twice a year. Those that service their own cars must remember there is more to servicing these cars than just doing an oil/filter service every once in a while.
If one lets this go the stuff go it can collect to the point the compressed air may not blow all of the stuff out and then the bumper cover has to come off and condensers unbolted and swung out of the way to allow for a thorough cleaning. Afterwards then the blast of air can be used to clean the accumulation of trash and dirt out of the ducts.