Chas, one thing I haven't noticed anyone addressing is that arrangers do NOT have to be only used by performers doing covers.
They are imo the best scratchpad for composing original material whether using preset styles, adapting/changing preset styles, or creating new styles from scratch.
As a composing tool arrangers should live forever.
I hope BeachBum is not the only one working on original tunes here. Have been waiting for others to start adding new things. It is my intention to do some composing sometime soon.
Jim