You can re-import an entire spreadsheet IF you have selected the option to "Skip" duplicates (If Transaction exists - Skip (other options are Overwrite, Append, Duplicate)).
(YMMV, make sure your configuration is correct with a small sheet first.)
In version 12, if a sheet failed, I would simply copy the last failed Ref number from Zed Axis Import Log, then go to that sheet, duplicate (copy it in Excel), and delete everything above it on the copy. This left my full sheet intact, while giving me a new sheet with the missing data to pull from. Make sure to select the correct sheet under Excel Options.
In version 13, I see that it seems to sort the sheet by Ref #, which may be different to how your sheet is sorted. No big issue if you re-import the entire sheet and let it skip duplicates, but if you try to use the method of last failed Ref number, ensure you have sorted your spreadsheet by Ref number, otherwise it may not match up (Again, YMMV, make sure your settings are correct before applying someones else's methods, also back up your files before importing or testing imports to make sure errors aren't harder to fix than need be.)
I haven't tried a large sheet with ver 13. in Ver 12 I could get up to 500 rows, but failure rates were high over 300. I have since dropped to 300 lines per sheet, and have a 99.9% success rate (where data is correctly arranged). I'll update next time I try a large import.