This is a great inexpensive boost chip https://datasheet.lcsc.com/szlcsc/1811201211_hengjiaxing-HX3608_C296278.pdf but im not sure if it will accept up to Vin max for VEn pin. It says the minimum is 3.6v for VEn but it doesn't say maximum for the pin. Typically for swhiching ICs its up to Vin max but Im not sure about this part.
The application schematic shows EN connected to Vin, which implies En is rated up to the supply voltage.
The minimum voltage for EN isn't 3.6V, but the voltage at IC's GND pin.
The thresholds for EN are only specified for a 3.6V supply.
In reality, EN can probably be slightly higher than VIN and slightly lower than GND without causing any issues: +0.3V above VIN and -0.3V below GND is probably acceptable.