On March 11, 2021, CRA added the following guidance in respect of T4 summary submission:
If you take advantage of the TWS, you must include your TWS amount on Line 82 of the T4 Summary, as this amount is part of the remittances you made to the CRA in 2020.
It is noted that T4s were due on February 28, 2021. No additional comments were provided for situations in which the TWS was not reported in this way.