Alternative layouts are a risky field because people have totally different typing habits. So you cannot really talk about layouts in general, nor evaluate them, without knowing the user.
That's why I try to avoid advocating layouts – even my own one. ;)
However, there's a quite obvious and risk-free modification: numbers.
The gist of the trick is that the frequency of numbers is different but sort of descending: 0123 are the most frequently used ones and 789 are much rarer.
Well, it depends on the corpus but in the author's experience the order is 1023456879. I know of some hardcore layout-geeks who would arrange their numpads that way but for the sake of learnability we can group the digits, and the result is something like this:
So with numbers on a logical layer, instead of putting 456 on the home row (as it's done on the classic numpad) you can put 123 (Pnohty) or 0123 (my approach) in the best positions:
With Pnohty, the numpad is arranged in almost the same way as I've used it for more than a year now. I tried to find the old blog post I read about this for the first time – without success. Will update this post if I find it.
The point is: In programming, many short ordered lists, array indices, etc. may end at 3 so you can do a lot of stuff on the home row.
I type a lot of dates, even datetime values, so e.g. being able to type today's date (2022-01-30) exclusively on the home row is important for me.
That's it. Try it out. It takes some time to retrain your muscles though. I found it more challenging than getting accustomed to swapped alphas – probably because numbers are used less often and sporadic.
I don't want to comment on the other features of Pnohty, those depend more on your workflow and typing habits.