If Lenovo forum users say it doesn't work then it probably doesn't work. The laptop charger it came with is the one safe bet since it's built for it. Not all laptops take USB-C charging when they have USB-C, in fact, on the PC side, many laptops reject certain chargers, some even require their own brand, like I heard HP makes you use HP USB-C chargers on some models (maybe not all). It's also made worse by the spec only allowing 100 watts, so laptops like yours that use more power can't really use USB-C without throttling things like CPU and GPU down (though Dell has a proprietary implementation that ups the available power to like 130 watts). Apple has even chosen low power GPUs on purpose to keep the power draw low enough for USB-C, to the detriment of past 15 inch Macbook Pros having lower GPUs than comparable Windows machines.
Usually lower power machines (ultrabooks and tablets) with USB-C would be fine though with most USB-C chargers, since they have a low power draw and the 30 watt chargers are widely available and provide plenty of power for ultrabook machines.