Found this from the Singapore ABTC website, which might be of relevance:
https://eabtc.ica.gov.sg/eabtc/index.xhtml
"For the purpose of providing greater convenience, all ABTC holders (with or without pre-clearance) can also enjoy extended border facilitation, i.e. they would be allowed to use the APEC lanes in all participating economies,
except when entering Chinese Taipei (to use designated lanes in Chinese Taipei, card holders must obtain prior pre-clearance)"
As a US, Canadian (and Chinese or HK) ABTC cardholder, you won't have prior clearance for Taiwan.