That was good advice above. I gave this some thought earlier, and came to similar conclusions for acoustic guitar application: one of the multi-effects, a compressor, and reverb (or modulation, on the mild side).
Not knowing the OP’s musical preferences & available effects, I’m assuming at least the H910 / H949 algo from an H9 Core. That would cover pitch shift / 12-string simulations, micropitch detuning, & parallel delays.
SpaceTime is a logical choice. The other multi-effects might be a little over-the-top for acoustic (although I really like ModEchoVerb’s selection of mod FX in isolation). PitchFuzz on acoustic? Hmmm …
My choice for compression would be DynaVerb. It would satisfy the reverb ‘requirement’, while adding that killer OmniPressor versatility. I’d say DynaVerb requires a real familiarity with compression parameters, and how to adjust them to best effect. If the focus leans more towards fine control over equalization and routing – along with a ‘guitaristic’ approach – then EQ Compressor is the better selection.
And the 3rd? Phaser came to mind immediately, with lighter brush strokes. Some form of reverb would easily nudge that out, if currently unavailable. Each one of the delay or reverb algorithms brings a unique flavor & capability with it. SpaceTime bases its reverb on a plate, so Room or Hall would cover the standard fare.
