You’re no more than asking me to make a summary of the above posts.
Ok, let me present here what I understand about “n times larger than ” vs “n times as much as”.
As above posts have said, “n times larger than” may be understood in two ways, but the correct version is “If A is n times larger than B, then A = (n+1)B”. However, we can’t expect people are always so precise about arithmetic things in daily life, so on many occasions the two terms are used interchangeably.
I think what you are worried about is whether natives will misunderstand the intended meaning if the two terms are used interchangeably, aren’t you? Of course the chances are rare. You know, if the speaker is aware of the possible misunderstanding or needs to make difference about such things, s/he may avoid using the “larger than” thing. On the other hand, seldom would people make great efforts to differentiate 1001 and 1000. Would you?
I am sorry for not amswering your question technically.