Is there a specific reason that, when transliterating an English name, double letters are carried over into the Cyrillic? Specific example: My daughter's name is Tillie. This is an unusual name even in English, and so when we lived for a year in Russia, everyone had to come up with Cyrillic for it on the fly. Without exception, everyone who tried ended up transliterating it as Тилли. This seems odd to me, since the double-L in English isn't really pronounced as a double. It's mostly just there so that the name doesn't look like it should be pronounced ty-lee.
Would the pronunciation of Тили be noticeably different from Тилли? And if so, wouldn't the single Л actually be closer to the English pronunciation?