According to all this, the measurement of loudness (especially watching the true peak TP) seems a wise way to avoid unwanted peaks and distortions when converting digital audio to analog.
In the loudness measurements that I did with the Youlean Loudness Meter 2 plugin (in my first response), red marks are observed that indicate a true peak value above 0 dB (+0.5 dB).
However, the TP value in the loudness meter in Shotcut marks a positive value (728.5 dBTP) out of scale range (-50 to +3).
I should ask about this.
Finally I overcomplicated the answer to your problem.
Searching the forum, I found this.
I hope it helps.