Does it make sense to make non-key headings a < b > tag with a class of the required size h1 or ..... h6?

Question

HTML

Good day to all.
There is a page by type (landingpage) on which there are headings, some of which are important for search engines and have key queries, some of which are standard in type (reviews, how we work, and so on)
The question is how to do it right. Answer options
1. Select all key headings according to the nesting hierarchy, as top-level headings H1 ..... H2, and put headings that do not carry keywords in the < b > tag and assign it a class of the required size so that they look similar to the user and do not had differences.
2. Make all headings in H1 ...... H2 tags, regardless of whether they have keywords or not
3. Your own version

Answer 1

2
That's what headings were made for. The manual doesn't say "use hN only for keyword titles". In the recommendations from Google and Yandex, I also did not see this.

Answer 2

option 2.
On the page, you can use two H2, two H3, it doesn’t matter if there are keys in them or not, they were created for this