Another disavow question

The traffic on the website still dropping with each google update. The backlink profile is ~500 ref. domains
After researching other disavow related topics on the forum, I still have a few questions:

1) Should I disavow websites with a good DR but 0 traffic, 0 kw? (DR boosted by google redirect links ofc).
2) Should I disavow websites that 2 years ago had 3k traffic and now 30, for example?

My point is if I got a lot of backlinks from websites with penalties, my website can be affected somehow as well?

Also, does anybody has successful experience by disavowing toxic links suggested by SemRush/LinkResearchTools?

Don't disavow backlinks, instead focus on adding more backlinks and you will regain traffic

Disavow only the penalized ones or the ones which are highly spam or definitely a part of PBN. At the same time focus on more and fresh contextual backlinks from relevant websites to your niche