inefficiency exists in static esp_err_t _write_top_nibble(const i2c_lcd1602_info_t * i2c_lcd1602_info, uint8_t data)

[FrancoisLegerBe]

Some (most?) LCD1602 uses a ST7066U front end IC.
When using this IC, the storage of the data from the I2C interface occurs on the up to low transition of the EN signal.
Using three I2C transmissions is useless, as the EN low to UP transition does not do anything, therefore the _write_to_expander call before the _strobe_enable can be removed in the _write_top_nibble when using such setup. This will reduce the I2C communication load by one third.

Note: the EN signal is controlled by the FLAG_ENABLE value.