Is this an actual limitation, or are you saying that this is a bad idea?
"I would use a database like SQLite"
My concern is how the database would do this. Wouldn't it be doing the exact same thing?
Also, since the only way to append to a BLOB that I've seen is to do an "update . . . set this_blob = concat(this_blob,new_int)", wouldn't that be even less efficient?