This would likely lead to overweighting kata, actually. Users would vote it higher than it really is to get more points. It was changed to a 6 recently.

Don't mutate the input

My point is you do NOT need to know anything about the particular Morse codes, and you do not need any websearch skills to solve this (and the following) kata.

Using not very standart code table is a feature to move the focus of the solution from Morse Code to Python (Java, C# etc.) code.

First of all, you're wrong, please check Wikipedia.
Second, that should not bother you as the Morse Code table is preloaded in this kata and you should just use it without taking care of what's inside.