Non-animal based protein sources mostly have a different amino acid profile than animal-based protein sources.  Different plants also have a different composition. 

From looking a bit at the data myself it seems that if you mix different plant protein sources, you can get a good balance for most amino acids with the expectation of Methionine.

Mike from Renaissance Periodization who's a professor of exercise science suggests that a vegan can just look at the Protein digestibility-corrected amino acid score (PDCAAS) and use this as a factor for protein consumption to get the correct amino acid consumption as a vegan. 

From thinking about the issue myself, I would expect that you get significantly lower Methionine consumption if you do that then a person who uses animal-based products as their protein sources.

Given that a protein needs a very exact number of each amino acid to be synthesized, for essential amino acids like Methionine, I would expect their consumptions to be a bottleneck for muscle building which needs protein. Even if all the other proteins are in good amounts and thus the PDCAAS score is decent, you can drown in a river that's on average 20cm deep.

One possible solution would be to focus on high Methionine protein sources as a vegan and less on the PDCAAS (for a vegan protein source, soy is good at both) and just consume twice the amount of protein that a non-vegan would to get similar Methionine consumption. I'm not sure what the exact consequences of having all the other amino acids in excess happen to be.

Has someone thought more about this and come to a good conclusion about how to think about Methionine as someone with a mostly vegan diet who wants to build muscle?