Great questions Scott. I rather suspect you’ll be short on answers.
Ollie at Thiel Motorsports is one such guy who’s continually developing things for the 961, inc a big bore kit. But he’s very a difficult man to get information out of!
Stateside, I don’t know of any such outfit. There’s the Cotes boys North of the border, but I’m not sure if they are particularly performance orientated, they seem more focused on reliability and ironing out known issues etc.
To your points, I would have thought that the cam would be a source of power gains. The stock cam must be designed with a heavy focus on noise / emission reduction plus having to work with the stock silencers. Give the bike open pipes and a programmable ECU and I’d say the cam could definitely be enhanced. But I’m not aware of any off the shelf solutions.
I would have thought that even Norton’s would already have a half decent 3 angle valve cut these days, but I’ve never looked, so may well be surprised! But I’d also imagine that more work in this area and in the ports may yield some flow improvements. But once again, I’m not aware of any experimentation already done in this area.
Titanium valve won’t yield any benefit unless chasing much higher rpm, or wanting to lower valve spring rates (in order to reduce losses). Reducing losses by reducing spring pressures would be a good idea, but you’d be venturing out on your own calculating how much to reduce.
Increasing the CR is an area I’d be cautious about. This is already a fairly high CR for such an old Skool motor and it already runs rather hot. Increasing CR will increase heat, I’d want to satisfy myself that this was safe.
It might be worth considering leaving the motor alone and grafting a cheeky little supercharger on instead... jus’ sayin’...