Few things to keep in mind before making any choice:
1. Most of the time, the worst damage single backlink can do is ‘no benefit’. That’s the worst for any single backlink.
2. Spammy backlinks become problem when you gain too many in too short time. This happens when SEO person is taking shortcuts to rank faster and lacks knowledge about latest algorithm updates. It can also happen when your site is under negative seo attack.
3. In case if google decides to punish you for that, you should get update under ‘manual action’ in your GSC. But google isn’t very consistent about it. If your site gets punished by ‘spam brain’, you may not be notified at all.
4. You can ‘reavow’ a link. Remove it from disavow file and then resubmit it in GSC.
So, this is what you can do:
1. If you have strong reason to believe few backlinks are damaging you, disavow them. don’t make any other changes.
2. Track your ranks for next few weeks. You should see some positive gains or no difference at all
3. Then reavow them. Make sure they’re reflected under ‘links’ section in your GSC.
4. Track rankings again for next 2-3 weeks.
5. If you see a sudden drop, disavow them for good this time. If not, let them be in your backlinks.