While listening to diverse podcast in the naval months, one of the reasons of the superiority of British naval gunnery should have been the better British powder compared to the French and Spanish.
While I cannot comment on the Spanish, I cannot see anything wrong with French gun powder - assuming they used the same as the French land armies did. It was perfectly adequate to do the job. What should be so superior of the British gun powder??
Next, how was the powder stored on ships to prevent humidity ??
Lastly it is mentioned that the British guns had flintlock mechnisms and that those enabled a more calculated shot. I was under the impression that only HMS Victory had so and then again I see not that great advantage compared to the usual firing tube insterted into the vent which did ignite all of a sudden compared to lints.
Naval warfare is not something I'm entirely confident to say much about either, although my wife is distantly related to Henry Digby who commanded HMS Africa at Trafalgar but that does not, of course, add to my meagre qualifications.
Looking further into the subject of gunlocks I see the first RN trials with gunlocks were in 1755 on HMS Invincible and 12 other ships but not approved by The Admiralty for general use until 1790. They seem to have been in general use at The Nile in 1798 when they were, apparently, reported on favourably. I am fairly confident that Victory was not unique in this context in 1805.
Be that as it may, there seems to be something in the claims about quality of powder and the effectiveness of gun locks but, on the other hand, a French gunlock dated "An 13" (1804) came up for auction in 2015. So where does that leave the claims that the French and Spanish navies relied on linstocks at Trafalgar? I really don't know.
Like Jena, there is certainly a lot of popular repetition of received wisdom where Trafalgar is concerned, and possibly also The War of 1812 which strikes me as a 'score draw' as far as the actions between frigates, sloops and brigs are concerned.
Returning to Trafalgar though, you have to remember too that Nelson remains a national hero, which tends to elevate the status of everything connected with him. There is nothing, for example, like Trafalgar Square or Nelson's Column to celebrate Wellington (yes he did get Waterloo Station but a railway station it is not quite the same thing) or, I dare say, any other British historical figure.
I think The War of 1812 may be subject to as much received wisdom as Trafalgar or Jena.
Anyway, have a look at this article which has number of contemporary pieces in it from primary sources. I think you'll find it interesting:
https://www.tandfonline.com/doi/pdf/10.1080/21533369.2005.9668349
Let me know what you think of it.