Well, it's all personal preference I'd say. The first version of SQs fold down Biz seat (2006) had an even harder sleeping side than the 2013 one which was softened a bit because many pax complained. My personal choice is 2017 Biz seat on A380 when it comes to SQ long haul Biz, but then my next two flights are on an A350 .

While admittedly I do follow your advice and use a second blanket (if available) for extra padding (call me soft I guess), I was more coming from the angle that you can get a mattress pad in Biz with other carriers, e.g. NH, LH etc., as part of the product. Ohh and I wouldn't call that SQ "blanky" a duvet

Now just to make sure, don't get me wrong, I'm not saying LH's Biz seat is better or even up to par to SQs, just that there is extra padding available. And most importantly I would not agree with the thread title that SQ Biz seat is shockingly bad, just that it is not perfect in my book for what I like. YMMV.