In the first week of April, 2018 Tomas Rokicki resolved all of these and found 5 errors.  They've been corrected, and the technical details are below.  



3 different types for the 5 errors:
Errors #1 and #3:  The correct solutions weren't recorded (an original .out file verified error #1 was solved at the correct distance).  They thus ended up in higher-distance searches where non-optimal solutions were found.  (In 20moves, some solutions were recorded with a tedious copy/paste method prone to error.)  

Error #4:  A segmentation fault (core dumped) occurred causing only 56 of 61 characters of a line to be printed to file.  This was corrected for a spreadsheet, but not the .out file until now.  

Errors #2 and #5:  Peregrine had a feature partition=batch or partition=batch-nice (jobs of the latter type being interruptible by jobs of the prior type).  Originally I was using batch-nice for my single-node-auto-switch runs, but these did not checkpoint easily.  I eventually switched to batch so I didn't have to checkpoint, but I forgot to reset a variable in my code from 13 (for a checkpointed job) back to 1.  Instead of searching distances 1-13, the first search only searched distance 13 (original .out files showed only distance 13 results).  The second search (distances 8-13) caught any/all problems but these 2.  All affected ranges have been triple-checked by me with the correct first search (some solutions including these erroneous lines were less than distance 13), but no further improvements were found for the .out files.  



5 errors:
Error #1:  line 8392 of 20moves used to display
D1U2B3L1R2F3B1R2F1B1D2U3F2D3R3F2B1D3L1R1F3L1  (15sp*)
now
D3U3L1R2B2L1R2F1L2R1D2U3F1B2D1F2B2L3D1U1B1D2U1  (14sp*)

Error #2:  line 14781 of 20moves used to display
F2B3D3U3L2R3B3U3D2U2F2B3R2F1B2D3U2B3D3U2L2R2  (13sp*)
now
F2B3D3U3L2R3B3D2U1F2B3R2F1B2D3U2B3D3U2L2R2  (12sp*)
(the only change to the twist sequence is U3D2U2 is now D2U1)

Error #3:  line 32583 of 20moves used to display
L3R3F3B1L2R1D2U3L1R2D2U3F3F1L1R2D2U3L1R2D3U2F3B1D1U1 (14sp*)
now
F2D2U3L2R1D3U2F3B1L1R3D3F3B2D2U1F3B2D2U1R2  (12sp*)

Error #4:  line 30462 of C2va2 used to display
D2U1F1B1D2U1L1R1F2B3D3U1L1R3D3U1B3L3R3D1U2L1R1D3F2B2  (1
now
D2U1F1B1D2U1L1R1F2B3D3U1L1R3D3U1B3L3R3D1U2L1R1D3F2B2  (14sp*)

Error #5:  line 59678 of C2va2 used to display
L1R1F3B3L3R3U1B2D1U1L3R3D1U1F1B3D2U1L1R1F1B1L3R3 (13sp*)
now
L1R1F2D3U3L3R2D3U3L1R1D1U1F1B1L1R2D1U1F2L3R3  (12sp*)