"Loopers have unique hardware requirements, i.e. lots of memory. General-purpose guitar processors like the Axe-Fx don't need the amounts of memory that loopers require and adding that memory for a single effect would increase costs, probably considerably. Furthermore the processors used in products like the Axe-Fx are limited in the amount of memory they can address. The DSP used in the Axe-Fx III is the most powerful commercial DSP available but it's still limited in it's memory address space. Also, most loopers trade off bit-depth and sample rate for loop time. Therefore you're unlikely to ever find a multi-effect that has the loop time and features as a dedicated looper. If I were to make a dedicated looper I probably wouldn't use a DSP but something like an ARM with a lot of external address space. There isn't really much audio processing required, it's mostly memory access."
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