I can only confirm samples are much required. Mold maybe not so much, but colors definitely.
More than just a few of the colors displayed in the chip design tool are WAY off and look completely different on the actual material.
You alrady had the example with dark green and dark blue but there's even more, e.g. the browns, butterscotch, DG orange, DG saturn, the normal blue, DG peach, orange...
I'm currently working on a custom CPC set myself, and if I didn't have color samples at hand to do a sanity check on each chip's body/spot palette, I'd probably have ended up with a bunch of barely distinguishable denoms without knowing about it up front. Even with the samples, I am still highly undecided, but in the end I will at least know exactly what I'm going to get before I order.
And yes, I confirm, the overall design will look completely different when you put your inlay graphic on it. You don't have to design everything, but finalize at least a draft for one denom's label and then slap that on all the chip mockups - that will already enable you to get a much better impression.
Regarding your inlay background graphics, neither of them look very appealing to me. I feel they are too uneasy on the eye. Any text you put on that will likely be hard to read, even when you put an outline or drop shadow around it, as the background just distracts so much. If I were you, I'd choose a smoother graphic, or heavily blur the ones you have, maybe also desaturating and brightening the overall graphic, and maybe slightly tinting it in the chip body color to have it blend in better. In addition, the straight lines from the wood and brick wall graphics heavily clash with the rounded borders of the inlay and the overall chip shape. Aesthetically they don't fit in there at all imo.