Took a look at Do Your Clone as an alternative to Macrium Reflect Free for USB sticks -- they added support for USB sticks in version 8, but the free version is still on v. 7. And it seems to work for me, though there's no option to save a disk image to use as a backup -- the only destinations provided are the other attached disks or drives.
Do Your Clone uses [I assume older, from 2018] files and drivers from EaseUS -- running the app without installing it, and so without the 2 drivers, EuDskCp.sys & EuEumDk.sys, meant getting the "Failed to open..." message others are reporting. Running setup added the 2 drivers and everything seems to work fine.
Besides adding the two drivers, everything else is contained in the program's folder, which comes in at just over 80MB, with I assume a little bit of bloat as not everything in the set of EaseUS files appears to be used, e.g. VssFreeze-XP.exe, since others have have commented that it won't work in XP. Those drivers have the biggest impact on the registry, though it did cause a rewrite of the Component hive, if you don't like all that registry churn -- stuff happens, and in this case with a recorded 300K+ new registry entries from rewriting that hive, there's a slight bit more chance for something to go wrong.
Because of the 2 drivers Do Your Clone won't run portably or from a bootable USB stick, e.g. one with WinPE, but in situations where you'd need a bootable USB stick, e.g. cloning a disk to a laptop hard disk, restoring a backup with Macrium Reflect has always worked fine.
Do note that when you're cloning one disk/partition to another and both hard disks or partitions are attached internally, you can run into unintended side effects. Windows assigns each partition a unique GUID, and you can't have the same one twice, which is what happens when you clone a disk/partition. As long as it doesn't contain Windows or the Windows boot partition the fix afterward is as easy bringing a disk/partition back online in Computer Management -> Disk Management, which causes Windows to issue a new GUID. If Windows &/or the boot partition is involved you *may* have to change the boot drive order in the BIOS &/or edit the BCD [boot files]. Some image backup software will *try* to fix things for you, but if you're doing something like moving your Windows install to another disk, you'll want to check regardless to see which internal drive you're booting from, and which disk you're running Windows from. It's entirely possible to for example add an SSD, clone the Windows install from your old hard drive, and wind up still booting to and using the original installation rather than the new copy on the SSD.