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There are benefits from using higher voltage panels that can be realized when a system is designed for an MPPT controller. An MPPT controller can also be the centerpiece of a DIY converter.
Input voltage is a balancing act between absolute efficiency (requires lower input voltage), the ability to overcome self-consumption losses under all conditions (requires higher input voltage), wire size (higher input voltage), and shading mitigation (higher input voltage).
MPPT manufacturers always specify a maximum voltage coming into the panels; some also specify a minimum or optimium voltage.