Roland and Korg's Guitar modes are utterly different beasts...
Korg is not primarily a realtime thing, but more a tool for creating authentic strum patterns for styles. Roland, OTOH, is strictly realtime ONLY (or record into an SMF), you can't trigger the picking patterns from a style. Yes, you can record the pattern into a style, but you lose the authentic guitar voicings and inversions as standard NTT's (note transposition tables) are used from that point onwards, rather than the guitar specific NTT's used while Guitar Mode is active.
One can only hope Roland find a way to combine Guitar Mode AND style mode, because essentially, it's utterly useless as is for styles, unlike Korg's version. Just one in a long list of brilliant ideas that Roland got ALMOST right!
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An arranger is just a tool. What matters is what you build with it..!