Zerolemon 30,000 mAh, definitely impressive based on reviews. However...
1) While it says it's compatible with notebooks and MacBooks, it doesn't appear to be designed withPower Delivery (PD) (their 20100 mAh model does appear to support PD though). So only expect those to trickle charge an already charged up computer. If it's dead of low on power, you won't be able to use the device AND recharge it at the same time. I find it odd that the Amazon listing doesn't show the wattage of the Type-C port. If it's 15w or 30w it will not keep up with usage. But if it's 45w then it's a decent notebook battery backup.
2) The two reviews showing photos of the devices burned up, or burning, are of concern. Yes, plenty of power banks have caught fire. But it's telling that Amazon reviews of Anker, RavPower, Aukey, Jackery, Zendure, iMuto, etc...don't seem to feature reviews involving terrifying fires. Just something to keep in mind.
I have the iMuto, Aukey, and just got the Zendure PD models. Work great powering a MacBook Pro.