Using more wood as construction material helps to tie the CO2 for longer period.

This. Early trees sequestered a whole bunch of carbon in their structure (and there wasn’t efficient methods of breaking down lignin at the time, so the carbon stayed in the ground instead of rotting and returning to the sky). If we build long-lived structures out of wood or other carbon bearing materials whose carbon source is the atmosphere, we’ll be doing the same thing as trees but with human civilization as the organism.

Sounds like the real question is, how does 1 hectare of stick frame buildings compare to 1 hectare of mature forest? What stores more carbon-per-hectare, and how many years does the building actually lock up that carbon?

While a hectare of forest may be "only" CO2-neutral, a hectare of buildings are typically net CO2 emitters.

Yep, but reaching equilibrium once we've removed enough from the atmosphere is fine.

Of course this strategy does have to go hand-in-hand with drastic emission reductions to prevent use getting back to the same point and having nowhere else to put trees.

Yes, but that takes 50 years at least.

In the 2070s things will be very different.

We already have all the pieces needed, they just need to be connected in a better way.

Forests need to be managed to optimize for sequestration; log the right parts at the right time, replant. Also need to invest more in controlling forest fires (hell, use the military if that's the only way to get the budget).

At the other end we need to reduce burning wood for fuel through other renewables and put more lumber into building.