While I would agree that this is broadly true, I would contend that this only applied to working with larger PCR levels of DNA, and I would further contend that Stefanoni had very probably never received proper training in low-template DNA work. I strongly suspect that Stefanoni either entirely "winged it" when it came to LCN work, or that she had a small amount of knowledge-by-osmosis that she deemed to be sufficient. Either way, the evidence shows starkly that she was not only incompetent in the area of low-template DNA analysis, but also that she was mendacious and obfuscatory in trying to cover up her incompetence in court.
And I also agree with your submission that Stefanoni had probably never been properly trained in giving evidence in court. In addition, I strongly suspect that Stefanoni had scant (or even no) training in working crime scenes. In fact, that is possibly the most baffling and inexplicable thing - that a lab analyst such as Stefanoni was leading the crime scene analysis and evidence collection. It's incredibly unusual for this to ever be the case, since a) substantially different skill sets are required for each role, b) lab analysts tend to be educated, trained and qualified solely in the specialised field of lab analysis, and c) it's far better practice for the lab analyst to have no prior connection to the evidence being analysed - for two key reasons: 1) the possibility of prior contamination, and 2) the need for the lab analyst to see the evidence without any preconceptions or other information about it, which might result (either consciously or unconsciously) in a biassed interpretation of that evidence.
ETA: IIRC, Stefanoni was only in charge of the crime scene investigation and evidence collection because Mignini specifically requested it. I'd like to know a lot more about how and why a PM from Perugia could draft in a lab analyst from Rome to head up the crime scene evidence collection, especially when there must have been plenty of specialist crime scene investigators sitting in the Perugia police HQ, and when there would have been reams of high-quality CSI specialist officers based in Rome (had Mignini wanted to get the best possible CSIs on account of the importance and high profile of this case). So IMO it's highly baffling why Mignini requested (and obtained) Stefanoni to head up the CSI work, and how/why he was allowed to do so..............