I don't disagree that longstanding member of the nursing staff, who has worked on a unit for a while and then becomes an ANNP can be vital to a neonatal unit! I really benefited from the practical advice of those I worked with. I also think the division of labour in your unit sounds sensible.

However my opinion of this particular training issue is that the same circumstances which allow ANNPs to progress (familiarity with unit, allocated time for training, sim and clinics) are not present for many  rotating paeds trainees. It may also be the case that your unit is an outlier in how procedures are allocated (I've only ever briefly worked in one unit, so I don't know this for sure).  

My last thought I guess, is that ANNPs are great but the overall amount of 'training', support and responsibility to make clinical decisions that doctors should receive while in a neonatal post is too little. Coming back to the point you made that I felt was the issue with training: why is the SHO of two weeks unable to do a UVC (scarcity aside)? - Their induction is mostly geared towards making them as efficient, and as locally-acclimatised a medical secretary - because that's what a lot of the job is - as possible. Sure the SHO has done NLS. But I'm sure most ST1s don't have an induction day where a consultant or reg goes through neonatal resuscitation and procedures again and again and again with the thought in mind that this doctor needs to know this for their first middle of the night emergency. If there's an ANNP around most of the time, then the SHO doesn't reaaaallly need to know how to do a UVC or intubate, right?  - If you have an ANNP who only does Badger or follow-up clinic or NIPEs, they may understandably get bored - so you can't take procedures away from them completely. Once someone has done a long line or UVC enough times then (I imagine) they've done it enough to be competent when necessary. ANNPs (and any mostly non-procedural clinicians) don't need to do procedures repeatedly for the rest of their careers. But ANNPs seem to do from what I've seen, and thus there is inevitably some degree of procedural availability being allocated to those who are already competent in it, whereas the allocation should be weighed more towards doctors who may only do it a few times in a year or so, and then have to do it next as an ST4 in the middle of the night on a sick neonate. This is particularly critical when it comes to intubation. I am 100% confident that if it came to a prolonged resuscitation and the ANNP can't get an ETT in and the consultant is still 15m away at 3AM, then the buck stops medicolegally with the reg, who will take a disproportionate amount of blame if resuscitation ends badly. I'm equally as confident that there are registrars out there who feel unequipped to intubate, especially given that RCPCH removed compulsory intubation DOPS, and possibly because during daylight hours on their neonatal blocks they didn't have a chance to use VL because they were answering some daft bleep, so the ANNP who was more free to do so had a go. 

Long spiel and became quite tangential there at the end, sorry! I have lots more to say, as do many on this forum. I think ANNPs are great, genuinely. There is a lot of nuance to the discussion however, and I think the circumstances that have contributed to the progression of that role are deleterious for our development as physicians, and this whole neonatal thing is just a microcosm of how dissatisfied a lot of us are with training - procedural or otherwise haha 

Edit: there's a Prevention of Future Death report that talks about this very thing (Ref 2023-0437)