Ok, good to know. That helps tailor the advice.
1Password's LastPass importer is in a state of flux, but should be pretty robust. Version 8.9.14 https://1password.community/discussion/comment/673941/#Comment_673941 to handle attachments (I don't seem to have that ability in the 8.10.0 beta version). Given that, I think this would be the best method to use for importing your LastPass data (if it works for you - it failed for me in my free account, which has many very old records and has UTF8 characters which are not yet handled). See also:
https://releases.1password.com/mac/8.9/
You can start by comparing the record counts in both systems to get an idea if all the records were transferred, but there may be some discrepancies, and it's worth determining where these occur. MikeT also highlights the possible issues in the thread.
It would be worthwhile to review a few sample records in the various categories, so that you can 1) become familiar with the mapping that occurred, and 2) verify the data. If you get a successful import, I would be less worried about using the native 1Password (or 1Password.com) importer than a LastPass CSV export.
