as long as the Taiwan spouse will adjust or CP with the China-born proincipal using the same underlying petition.
Example 1, Taiwan spouse file I-485 based on principal's EB2 I-140, both visa numbers (spouse application also takes a visa number from the quota in EB category) will charge to Taiwan, which is current for EB2.
Example 2, Taiwan spouse already has GC, or not plan to get GC, or filing for GC based on another petition. The China-born EB principal will have visa number charged no where else but only to China, which is subject to a longer cut-off date.
Example 1, Taiwan spouse file I-485 based on principal's EB2 I-140, both visa numbers (spouse application also takes a visa number from the quota in EB category) will charge to Taiwan, which is current for EB2.
Example 2, Taiwan spouse already has GC, or not plan to get GC, or filing for GC based on another petition. The China-born EB principal will have visa number charged no where else but only to China, which is subject to a longer cut-off date.