So, for those arguing that section 3 of the 14th amendment doesn't disqualify Trump from being on the ballot in 2024 based on what he is known to have said and done on Jan 6, 2021 to instigate, encourage and fail to defuse an insurrection, is there any further action Trump could have taken that would have disqualified him?

Oh, of course. If he had taken actions that were more inescapably engaging in an insurrection - personally organizing and directing military units to attack government forces and seize control of the government through military encounters like in the Civil War - he certainly would have been tried and convicted of the crime of insurrection by now. One reason this is such a contentious issue, and why SCOTUS had reservations, is because they clearly believe that reasonable minds can disagree over whether Trump's actions constituted engaging in insurrection. Legal and political maneuvering combined with a speech to the crowd that contained martial rhetoric but no explicit commands to engage in unlawful behavior could constitute engaging in an insurrection, but it's by no means as clear-cut as whether someone is or is not 35 years old or has been elected President twice already.