I wouldn't have thought that making the power will be an issue, Phil.
As far as new vs evolved goes, I suppose manufacturers have to play the safe game and even tweaking existing models will involve extensive research, development and testing. Never mind the cost.
Although not a PCP fan, I know the little Ultra has won over many fans over the years due to its "no-nonsense" and tough appeal. Seemingly very accurate, too. A couple of years ago when I was being a little flirty in my thoughts, I researched the single shot version a good while. And most of what I saw was good. Being a springer man, the simplicity and cost saving of the single shot layout appealed. One of the reasons I was half (only half) considering the PCP was that I often have weird "nervy" pain and sensations down my arms.
Then, about a year and a half ago, I was given an Air Arms S410 Carbine. Preferring single shot, I bought one of these cheap (about £7) SMW single shot loaders for it. In all that time I put one mag through it when I was first given it. Five shots a few days later to try out the single shot tray. And about 20 shots last May. So, a good job I was given this for free and that I'd not invested in one.
However, if I was in the market for a hunting PCP, the little Ultra would be on my shopping list.
Now, where's that new Armoury Road Boinger?