In my method,
an initial vowel will do the same trick.
However, if the middle vowel is hardly there, such as for words “acre, apple, eagle”, I will not double the value of the first consonant. Instead, I will use the assigned value for the initial vowel. I may also use that approach even if there is a clear well sounded middle vowel if the word begins and ends with a sounded vowel, such as Atari.
The idea behind all this is to increase choice and flexibility in your system.