plawolf
Lieutenant General
Those are expensive, maybe the results did not justify the cost or possibly their more complex manufacture would prohibit timely production of aircraft??? just throwing out a couple of possibilities
They were widely using them on J10s and J11s for years. It just makes no sense that they would be deemed justified for conventional fighters but too expensive for a stealth fighter, where the smallest RCS spike might render all the other expensive stealth features worthless.
In all probability, they probably developed new materials to perform the same function better and/or at lower cost/weight, with the lack of golden tint merely a cosmetic consequence.