Should salaries of employees working on eligible projects/activities be considered eligible OpEx?

Example: a consultancy firm provides GHG calculation and reduction strategy services, generating revenue (turnover) from these activities. The project is eligible under the EU Taxonomy.

In this case, should the salaries of employees working directly on the project be considered aligned OpEx? Do you have examples of similar cases?

I would love to hear your thoughts on this, thank you in advance!