Hi there. I recently installed Mojave on my main device and attempted to create a boot drive for my older iMac which is in need of repair. Like most of you known, Mojave no longer shows previously purchased macOS in the app store. Apple has even come out and said to use devices with High Sierra and before to make bootable USBs the traditional way. I kept my older MacBook Pro with the intention of a project but now I simply want to use it make several USBs of prior macOS and have them ready just in case apple removes all macOS from the app store. I don't know if this is rational or not but, I 'd rather just be safe being that I'm new to all this. My question is how to best go about downloading and formatting several OS to different USBs per os. Should I just repeat the traditional steps several times, or is there a faster way for multiple USBs? Please reply with any comments or suggestions on specific steps and methods. Thanks.