Its been said on this thread or another that persea have compatibility issues but the only paper I've been able to find that hybridizes a hardy NA persea to p.americana is from the 50s! And iirc its only persea bubonia (red bay) and not persea palustris (swamp bay) and p.palustris might be slightly closer

Source: MOLECULAR PHYLOGENETIC ANALYSIS OF THE PERSEA GROUP
(LAURACEAE) lang li
Even in that 50s article there were some hybrids between persea species even tho the borbonia crosses failed. Has there been other documented experiments on interspecies crosses in this genus? Especially with p.palustris
Edit: The 50s persea hybridization paper I'm referencing:
https://www.avocadosource.com/Journals/ASHS/ASHS_1954_63_PG_239-242.pdf