I understand your reasoning, but as Daniel has told you, the extra languages should not cause the overheating in your computer. So you can understand, a computer has several components that are used differently and react differently. Extra code for other languages occupies memory, which makes the download bigger and takes more space in your computer. Usually more code means more processing done by the CPU, there fore more heat. But, LanguageTool does not load the code from languages it does no uses, so there is no extra processing done, just for having those modules, therefore, no extra heating.
There are solutions to reduce processing, but they are very difficult, because they require optimizing the entire code, and they are tough problems to solve. It can also be done by simplifying a language, but it will become less useful and produce more mistakes.
The most likely reason for your overheating, is that your computer has the fans clogged. Another reason is that Linux has worst component management than Windows. I don’t say this to publicize, since I also use and prefer Linux, but I had already two computers in repairs due to overheating caused by the migration to Linux and its poor driver support - specially GPU drivers.
So, to clarify, would you request to reduce LT complexity and, therefore, its usefulness?