I have seen how someone was able to create a Bitcoin character for Computer/Latin Modern Roman although it is not a part of the font itself.
The capital ẞ does not seem to be a part of Computer/Latin Modern Roman and alternative fonts have been recommended in order to tackle that problem.
Importing the character from another font can also not be a proper solution.
So, I want to ask whether someone has managed to create the ẞ character in Computer/Latin Modern Roman style although it is not a part of this font but it can be added like the Bitcoin character shown in the example above.

$\Beta$closest to what you're looking for (though in CM/LM it's$\Beta$looks likeB(as it does in the font used here) – Chris H Dec 21 '17 at 16:58