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setSegments() allows you to only set a specific digit:
//! @param segments An array of size @ref length containing the raw segment values
//! @param length The number of digits to be modified
//! @param pos The position from which to start the modification (0 - leftmost, 3 - rightmost)
void setSegments(const uint8_t segments[], uint8_t length = 4, uint8_t pos = 0);
So if you wanted to blank the 2nd digit, it should look something like this:
uint8_t data[] = {0x0};
display.setSegments(data, 1, 1); // blank the second digit