When writing/saving a single string-value (e. g. in Title) as ID3v2.3 to a non-tagged/empty mp3-file, the required tag-size amounts to 2229 bytes, also when additional (four) fields are filled with the same value. But when several (all five) fields are filled and written at once for the first time, 2401 bytes are required instead. Which actually depends on how much fields are initially written together.
For example writing the value '0123456789ABCDE0123456789ABCDE0' sequentially one after another (multiple saves) in five fields results in 2229 bytes. Writing the same at once for all five fields, within one/the first saving action, results in 2401 bytes as total tag-size.
Is it possible to retain the minimum required tag-size automatically, perhaps as optional setting, even if it will slow down the writing process?
What's the reason for the (redundant) 'expansion' of the tag-container when all fields are written at the same/initial time?
Is there any difference in performance and necessary reading-time of mp3-tags whether it's written sequentially (lower tag-size) or altogether (larger tag-size) for other applications/devices?
(Custom columns %_tag_size% + %_tag_size_prepended% can be used for display of required bytes.)