I could've sworn this was discussed before, but I somehow can't find the thread. @Toe_Save help me!
This blog has some pretty good suggestions and reviews are pretty on point with very forward point system. I've been to a few of the places they've recommended and his point system is spot on.
Personally, I think if you're in Taiwan, you gotta drink Taiwanese brews. I'm not a beer nerd, but I do prefer a nice pint off the draft as opposed to something that has traveled 5,000 miles.
OP I know you said Belgium brews, but try these...
The above has a location at the top of ATT4FUN by 101. On a summer evening, probably one of the best places in the city to have a beer.
The Taiwan Beer factory just re-opened its Biergarden-like bar and it's a 快炒/100 dollar plate kind of place. They serve the freshest of 18 day Taiwan Beer in the city. I haven't gone after they re-opened, but I remember it being 550NT for 5000cc of 18 days in a small keg (approximately 9-10 pints). Live music on certain days too!