GnuCash Ver.5 and up - copying settings, especially reports
To copy the settings, particularly the reports you have already made, to GnuCash Portable, the instructions on the page at https://portableapps.com/support/gnucash_portable#local_profile haven't been updated for a while, and no longer work.
The new directory for the reports file (saved-reports-2.8, saved-reports-2.8-backup) and the other settings files, is at:
[drive]:\PortableApps\GnuCashPortable\Data\GNCDataHome