I must say I am also seeing a bad first layer just like the photos posted by @Scott. The filament is laid down thin in some places and thick/normal in others. The layer appears to be thin only when the print head is moving in certain directions and not necessarily over the same points on the build plate, just like the photos posted by @Scott. So it doesn't appear to be a bed leveling problem, and I don't believe my build plate is warped. Since it doesn't affect the print beyond the first couple/few layers, I don't believe it is a filament binding issue. The vertical tower rods and the ball ends of the connecting rods are lubricated. I am using FLUX filament. I have tried printing temps from 220 all the way down to 190. I have tried adding a z-offset, but I can only go so far with it...once the z-offset is high enough for thin parts of the layer look more normal. the thick parts will no longer stick to the bed because the nozzle is too high.
I also see the twisting/rocking motion in the TRGBs that is mentioned in this thread. To see the twisting/rocking, I watch the TRGB that is moving the least while printing solid infill. I can see the vertical motion of the other two TRGBs inducing a twisting/rocking motion in the more stationary TRGB. All three of my TRGBs have this twisting/rocking motion. Though it's not what I would call severe, I would think any slop or play in the mechanical system is going to translate to the nozzle not always being in the correct position. I am wondering if this is possibly the cause of the inconsistent first layer thickness and some poorly shaped circles I am also seeing.
In addition to the twisting/rocking of the TRGBs, I am also hearing two audio anomalies. I hear a clicking sound at the top of the rear tower, with a slight twist of the belt when I hear the click, during downward motion of that rear TRGB. And I hear something like a whine or rub at the top of the left tower (I'm pretty sure it's not related to the extruder motor or filament) during upward motion of that left TRGB. I'm not sure if either of these have anything to do with first layer problem.
Later today I'll try to get a video of the twisting/rocking TRGBs and try to capture the audio anomalies and get them posted. I'll also get photos of the model part that I'm trying to print that shows the poorly shaped circles, and a comparison photo of the same part that printed alright on a Cobblebot Little Monster 3D printer.
My initial questions are: Did anybody with this specific first layer problem open a support ticket and get a solution? Would someone on the FLUX team care to make some sort of statement or recommendation regarding this issue?