Autocannons and late game HAA effectiveness

[kingbenno]

Playing Late into the game I noticed the autocannon tech being researched. The manual doesn't include any information about autocannons as far as I can see. Is it limited to 3 inch guns? I noticed the 3inch DP guns give massive HAA factor with the tech researched but how much does HAA actually matter late game? The after war statistics for me show around 65% enemy planes shot down by fighters, 30 ish % by sam and 1% each for MAA LAA and HAA. I understand MAA and LAA are for destroying missiles primarily but what is the point of HAA late game? Also how effective are autocannons against other ships, as I understand it there is an in game cap of ROF? Also what are the advantages of quality 2 guns, I played a UK game from 1890 to 1970s and only had level 2 quality guns for 5inch and my 4 inch was stuck at 0 despite having research at 12% budget all game and priority high for guns (the other only other high priority being ship design and later missile tech). Anyone else find they didn't unlock many new gun qualities late game? 

[sjpc302]

I have played a 1935 game as Japan (now 1948) and have unlocked no quality 1 guns for anything at all, which is pretty funny since I know Germany has better guns than that in 1900. There is a practical ROF cap, though I am not sure if anyone knows exactly what it is in RTW3 and it has been increased since RTW2. However the ROF cap usually only comes into effect when you have nearly the best possible firing solution.
Even before the missile age fighters alone will shoot down the majority of fighters, but that is expected. AAA is good for damaging incoming planes which reduces their effectiveness on attack, and that isn't counted as a kill. All forms of AA provide some level of suppression as well reducing accuracy of attacks and causing planes to abort runs. Apparently LAA is best per weight at this in the Interwar and WW2 periods so I spam a lot of it but expect few losses to be inflicted.