Uhm, what's the point of quoting papers from the 90's? 
I still believe this is a case of extremely premature optimizations, but would answer anyway:
1. Endianness is trivial to deal with.
2. That is irrelevant to fixed/variable encoding.
3. Not doing it is even faster.
4. Not implementing it is even simpler.
5. The code for not doing it is exactly zero bytes.
1. For portability of representation of constants between architectures.
2. Low working memory requirements.
3. Fast to encode and decode.
4. Simple to implement.
5. The code for the encoding and decoding of integers is very small -- only a hand-full of bytes.
2. Low working memory requirements.
3. Fast to encode and decode.
4. Simple to implement.
5. The code for the encoding and decoding of integers is very small -- only a hand-full of bytes.
I still believe this is a case of extremely premature optimizations, but would answer anyway:
1. Endianness is trivial to deal with.
2. That is irrelevant to fixed/variable encoding.
3. Not doing it is even faster.
4. Not implementing it is even simpler.
5. The code for not doing it is exactly zero bytes.