Here is another demo that enables installing & runing extension app on Wolvic. Check them out here: youtube.com/shorts/JmQnp...

In terms of pronunciation alone, reading '톼이스' seems a bit closer to the English speakers. 😅
IMHO, the rule seems a little different from the actual pronunciation because it is general rule for many cases.
In fact, there was a controversy that '오렌지', the word for orange, should be written as '오륀지'.

According to the rules, except some special cases described in 3.1.1 and 3.1.2, 't' is written as '트'. And 'wa' is written as '와' as described in the 3.9.1. 😀

In the rule for writing foreign words in Korean ('외래어 표기법'), you can find the phonetic symbols to Korean letter table ('표 1') in chapter 1 ('제 1장').
And there are notation detailed rules in chapter 3 ('제 3장 표기 세칙'). The article 1 ('제 1항') and article 9 ('제 9항') are rules for 't' and 'wa'.

I haven't think about that deeply, so I searched it a bit. 😅

We can find the rule '한국어 어문 규정' set by the national institution of the Korean Language:
- korean.go.kr/kornorms/mai...