Yes it’s removable. There is nothing behind it so would just have an open hole where your PSU is.
This is what I’m planning on putting in my Lynx case.
https://www.amazon.com/ELECROW-Portable-1280x800-Compatible-Raspberry/dp/B088WLRN31
https://keep.google.com/u/0/media/v2/1K2BKYUEOo9ORc-nwDzkQI8lWqwz\_b8PvaQ3fH15r5WJR4i96riEYmfTmsYXofA/1d3pjL4G1x-jDAndVlx1Ogx2q0zI9C6r8EJmEMrh7g\_GOTKveDEnTMHTVtamjHw?accept=image%2Fgif%2Cimage%2Fjpeg%2Cimage%2Fjpg%2Cimage%2Fpng%2Cimage%2Fwebp%2Ca...
https://keep.google.com/u/0/media/v2/1K2BKYUEOo9ORc-nwDzkQI8lWqwz\_b8PvaQ3fH15r5WJR4i96riEYmfTmsYXofA/1c5pkFXKmlvUFyiZoKv5L9FJ\_nVB6Mg8FPi2Oh-2vWu96OiyAKpxeSophLU17N3A?accept=image%2Fgif%2Cimage%2Fjpeg%2Cimage%2Fjpg%2Cimage%2Fpng%2Cimage%2Fwebp%2C...
https://keep.google.com/u/0/media/v2/1K2BKYUEOo9ORc-nwDzkQI8lWqwz\_b8PvaQ3fH15r5WJR4i96riEYmfTmsYXofA/13Wg85dOiyXTI5cjUUttvALMLAmIRUD8fIhxhY-ItIduHlLvTM0KuW2WTBzMQHQ?accept=image%2Fgif%2Cimage%2Fjpeg%2Cimage%2Fjpg%2Cimage%2Fpng%2Cimage%2Fwebp%2Cau...
https://keep.google.com/u/0/media/v2/1K2BKYUEOo9ORc-nwDzkQI8lWqwz\_b8PvaQ3fH15r5WJR4i96riEYmfTmsYXofA/1UGcio\_yogVBLHkO\_wcveKDUpCEu1k3HgnhcFF9Wao8W1oqBDuj4Gtap6xpVCNQ?accept=image%2Fgif%2Cimage%2Fjpeg%2Cimage%2Fjpg%2Cimage%2Fpng%2Cimage%2Fwebp%2C...