Parrotbee, That's a rather subjective decision. You'd have to make two plinths, one with Panzerholz and one with acrylic and then do your own listening tests. However, if you're talking about all-acrylic vs all Panzerholz (no mixing of disparate materials), I personally would choose Panzerholz or some other hard wood. Acrylic in layers with other materials can be used to effect constrained layer damping, nicely.
Basephysics, Perhaps you have some deeper understanding of how the Timeline works. I am not an owner of one, but I have borrowed one and long ago returned it to its owner. As I understand it, the Timeline is an idiot. It just flashes its laser(s) at a regular pre-determined interval such that if the platter is rotating precisely at 33.333... rpm, the laser "spot" on a nearby flat surface will not appear to move. In other words, the laser does not "sense" movement per se, it just flashes at a regular interval. If I am incorrect, please educate me. Now, if my understanding of the Timeline is NOT incorrect, then will you or someone please tell me how the Timeline can show us anything but the fact that the platter is or is not rotating at correct speed? If it only senses correct speed, how would it also be telling us about arm pod "movement", if such were happening? Let's say you put your finger against the side of the spinning platter, adding drag, and let's say that the Timeline continues to tell you that the speed is exactly correct. Does that mean you are not touching the platter, despite what your eyes and your senses tell you? "Arm pod drag" is no different from that.
I should add here that I do NOT think that the very large, well constructed, and well thought out arm pods used by most of the arm pod aficionados is actually moving. Henry, for one, made some beautiful constructions that are very massive, and his shelf is not a sheet of ice in fact. This has devolved into an argument about hypotheses.
As to "basic physics", Basephysics, you must be familiar with Newton's Third Law of Motion: For every action, there is an equal and opposite reaction. We all seem to accept the notion of "stylus drag". This is due to friction between the stylus tip and the vinyl groove. Correct? If stylus drag is real, then it stands to reason that the groove is also exerting an opposite force on the stylus tip which is in effect pulling on the tonearm. If the tonearm is mounted on an outboard free-standing arm pod, then the arm pod is subject to the theoretical possibility that it could be dragged by this force. (Again, I emphasize that I do NOT think this is a real world issue for a well built arm pod, until proven otherwise.) But in theory the arm pod might move. If this additional drag on the platter were to be overcome by the motor and servo so as to maintain exact speed, in spite even of the fact that the arm pod may be moving, then the Timeline would be oblivious to the whole thing. That's my point. The Timeline tells us nothing, zero, zilch about whether the arm pod moves or does not move, due to arm pod drag. The Timeline might be affected or might not be. It depends as always upon the tt motor and servo mechanism or other elements of the drive system.
That's my story, and I'm sticking to it.