Handle past gen transfer evochain for new evos

basically Math.Max(2, format);
we always want permissible evo chains when fetching encounters
Closes #2403 ty @Rayqo !

PKHeX.Core/Legality/Evolutions/EvolutionChain.cs

@@ -256,7 +256,7 @@ internal static List<EvoCriteria> GetValidPreEvolutions(PKM pkm, int maxspecieso
             if (maxspeciesorigin == -1 && pkm.InhabitedGeneration(2) && pkm.Format <= 2 && pkm.GenNumber == 1)
                 maxspeciesorigin = MaxSpeciesID_2;
 
-            int tree = maxspeciesorigin == MaxSpeciesID_2 ? 2 : pkm.Format;
+            int tree = pkm.Format <= 2 ? 2 : pkm.Format;
             var et = EvolutionTree.GetEvolutionTree(pkm, tree);
             return et.GetValidPreEvolutions(pkm, maxLevel: lvl, maxSpeciesOrigin: maxspeciesorigin, skipChecks: skipChecks, minLevel: minLevel);
         }