Thanks for reaching out. We have the SX1272 available to download here: https://www.snapeda.com/parts/SX1272IMLTRT/Semtech/view-part/
For the SX1278IMLTRT , you can try to create your own symbol and footprint using InstaBuild, just click on 'Build Footprint' and then once you have created the footprint, you can also create the symbol! https://www.snapeda.com/parts/SX1278IMLTRT/Semtech%20Corporation/view-part/
Hope that helps!
Answered 2 weeks ago.