Something to consider when building loaded dipoles.
the inductance required for loading a “short” dipole depends on the position of the loading inductor along the length of the antenna elements. one inductor is required in each leg.
If the loading is not inserted half way along the antenna, but say 1/4 along its length, the loading inductance required is reduced considerably and with that, the loss resistance is reduced. So with an antenna that already has links at various places along its length there are a number of opportunities to add loading to make it work on 160m. At the link between the “40m” length and the “80m” extension, instead of inserting a link, you could insert an inductor chosen to bring the antenna to resonance on 160m. How you make the inductor is your choice, but the inductors in the QRPguys trap antennas look fairly light and that design would probably be a good choice.
I think that approach may work better than adding a larger, heavier and more lossy inductance and another extension to the ends of the (already long) 80m dipole.
I don’t have an opportunity to try this out at present due to work pressures keeping me away from the shack, but this is an ideal application for the antenna analyser and I’d like to try it. I offer this idea to the experimenter.
73 Andrew VK1DA/VK2UH