Is that the whole objective? Just improve the quality of learned signals that already work? Those learned signals look quite good. Improving them probably will make no difference.

But if you do want to improve them, decodeCCF gave you the function number of each signal. MakeHex gives you 256 Pronto Hex strings labeled with function numbers. For each decoded signal, you could select the Pronto Hex string from the MakeHex output that has the same number and use that Pronto Hex string instead of the learned one.

Usually MakeHex/IrPanels are used when you are searching for missing signals, so you take the whole set of 256 signals and test each one and see what it does.