Hi
You do not say what type of USB drive you have - Removable Flash drive or 'Fixed Disk' type?
E2B will usually suggest the best extension - did you turn this off? if so, press SCROLL LOCK before you select an ISO to see suggestions.
First search this page.
https://easy2boot.com/add-payload-files/list-of-tested-payload-files/
DLCD is a variant of Hirens so see
https://easy2boot.com/add-payload-files/hirens-isos
WinPE based ISOs may boot as .isoPE01 from a removable USB drive or convert to .imgPTN file.
SystemRescueCD.iso should just work.
If you ran PimpMyDrive.cmd then a \_ISO\MAINMENU\PIMP folder will have been created - delete any .mnu file in that folder you do not want.
Use
set DEFMENU=0 in \_ISO\MyE2B.cfg file
to remove Set Timeout and defaults menu entry.
See https://easy2boot.com/configuring-e2b/
To re-order menu entries, rename the payload and .mnu files in the menu folder.
If you have any specific issues with specific ISOs, please give details.
Remember that when you run E2B Update, the update process will copy the E2B files back, so if possible, use MyE2B.cfg settings or ADD extra files, but do not change existing files.