Sustain Pedal Noise

An interesting point. To make the feature work would surely require a velocity-sensitive pedal, though. Do any manufacturers do that, at the moment?

With velocity sensitive i guess you mean feeling the resistance? In that case:
I dont know about any manufacturer, who does that. But you dont need such a pedal to make sense of this feature (Just a pedal with half damper function). You would need to imagine the sweet spot based on the sound. I already do that, but a realitstic sound would be of help for that. Also, many jazz pianists use this sound for percussive effects.
But i would love to have a resistance simulating pedal.

Pianoteq's sustain pedal signal is gradual - so maybe it's down to hardware for the effect to work. Unfortunately, otherwise, it may definitely be limited to on and off if your pedals are not built for gradual pressure sensitivity.

What still might help:

You can alter your pedal's curve to see if that makes some difference to reach your intended gains. Navigate by the small arrows left and right of the "Velocity Curve" box to find it. Maybe choose a longer slope or flatter ramp at top or bottom to alter how quickly or slowly the pedal activates as you press your foot down. You might avoid some 'bad practice' if you get the pedal point closer to what's natural to you.

I think Pianoteq's pedaling behaviour has gained much over the last few versions (including una corda) - always love the idea of more of this kind of improvement. It does separate it from a lot of other VSTIs. I never wish to put other software down, rather Pianoteq inescapably plays a lot more realistic than others to me.

My pedals are pretty solid (Kawai F-30, 3 pedal box), so I don't suffer lightness there, so they physically feel quite real - highly recommend this kind of kit - maybe that lends itself to a better sense of realism. In the past I've used very basic and plastic kit but honestly, it's not a waste of money to acquire solid gear, esp. if the idea is attaining realism and going beyond basics.

Have to say, I'm short on understanding on how the pedals really speak midi (I'll make a point to learn more soon - maybe I'm missing out on some extra ways of making the pedals better here) - but it does feel and sound to me like my half pedalling pays off a lot with current settings - but I'm all for more realism as we progress along the big timeline.

This Pedal Accent and Repedal Accent thread here on the forum by forum member NathanShirley is an interesting glimpse of other elements of playability related to the pedals which could offer a dramatically improved experience if in future Pianoteq can factor in elements from this as well as more detailed basic pedalling.

I agree with Qexl and aWc, solidity certainly pays off. DP-10 is not bad, it's what I have at the moment, and I'm not dissatisfied with it. Before that I had an old Yamaha pedal which Pianoteq's calibration wizard falsely identified as having half-damper capability, and I spent ages wondering why I couldn't get it to work properly!
Coming back to the original point of the thread, and Nathan's post about the repedal accent, I still think that there would need to be some sort of pressure sensor at the end of the pedal to be able to get different strengths of 'roar' when the pedal goes down.

On second thoughts...
If there was some way to calculate the final impact of the pedal based on its speed, then a fairly realistic simulation might be possible. It would need some very complex algorithms and tricky adjustments to avoid unwanted effects. But then, a few years ago, if someone had said it was possible to have beautiful, playable piano sounds created with just algorithms, I would have just laughed. And now here we are, with Pianoteq 6!