Thanks for your reply.
Could you please share the Test_004 in the standalone HydroDyn CertTest from FAST v8 as I couldn't find the file in which you provided the link below.
Not including Wheeler stretching will result in a lower amplitude of wave loading. But Wheeler stretching is known to overpredict the wave loading amplitude anyway. I already suggested the use of WaveMod = 6 in OpenFAST as a way to apply stretching, if needed.
I don't see any reason for you to run FAST v8 since you are already running a newer version--OpenFAST. And downgrading to FAST v8 would require some small input file changes. FAST v8 does not support Wheeler stretching either (but FAST v7 did). Regardless, FAST v8 is available here: https://drive.google.com/drive/folders/ ... sp=sharing.