For all aspiring RNA designers out there, I just wanted to bring to attention to this reference which has an excellent discussion of how Tm and Free energy (delta G) relate to each other, in particular what it means when you are comparing multiple molecules with the same delta G but different Tm’s, or with the same Tm and different delta G’s. FYI this bulletin is from IDTdna, one of the world’s largest commercial DNA (and RNA) synthesis company, so they know what they are talking about.
The reference refers to mfold and DNA “oligos”, but the conclusions are 100% applicable to eterna/viennafold and RNAs as well.