Split C. cumingii into C. cumingii s.s. of Malesia and C. taiwanense of Taiwan, the latter already recognized in our taxonomy and by Knapp's Ferns of Taiwan
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.