These are great supports and truly are like having a third hand. I'd say yes to mounting kitchen wall cabinets, especially if you are mounting them beneath a bulkhead that would provide the resistance necessary for the supports to securely lock in place. Just a note, the minimum height of these is 57". If that is higher than you intend to install your cabinets, Homer does market similar versions that are shorter and may better serve your purpose.
It is currently out of stock on the Home Depot online store but you can have Homer email you when they are back in stock.
Release tab directly above the pump handle.