Sorry can't help you. I didn't even notice any difference with the bushings on the frame since mine was painted. Though they should have sent you the extra washers (I've yet to receive mine), since 1 washer is not enough to lock the wheel down. As mentioned before, I found success with a 168mm * 19mm L 1lpm rear thru axle for that tight TA fit. Also like anything from AliExpress, don't expect perfect quality. Everything requires a little extra effort to get things perfect. On the plus side, at least the R088 looks cleaner than what Winspace has been churning out at more than double the price (voids in the bottom bracket)! 
Hi,
I imagine the bushings are not painted, so if they are different colors, I think you should notice it right away.
As for the rear thru axle, they told me that they use the same model on multiple frames, and they confirmed that the problem is the thread being too short (the 3 washers are used to compensate for this aspect)....they told me that the ideal would be a thru axle length 165mm * 17mm thread.
Regarding the finishes of the stops/ends of the thru axles, from what I've read around, they seem to be normal for a raw frame....as I already said, being inexperienced in the matter, I would have expected the same finishes as a painted frame, with the only difference of lack of paint, but evidently that is not the case (now I know).
As for the internal appearance of the frame tubes, nothing to say, they seem well made, apart from the internal of the drainage holes and mechanical FD that need to be sanded.
Now I just have to wait for the painter to be available (for the color I decided on the dove gray marbled effect of the Tarmac SL8 of which I have already posted photos....still undecided on the writings, I could apply stickers instead of painting).
In the meantime I have defined the setup:
- Sram Force Etap AXS 12V with PM Quarq (found used by a guy I know)
- Tagoola DAO Optimax Light 50mm wheels (23C and 30.5 external width)
- Elita One SL8 handlebar
- Wahoo/Speedplay pedals
- saddle: something I already have at home.