Magic Buckets does not require the extra step of entering username/pw in Garmin Connect to authorize the MPA data field to retrieve your current signature.
If a signature fetch fails with the MPA data field, PP will also display with a default value of 1200.
Magic Buckets alerts you when you are about to achieve a BT and also displays a BT medallion if you do (subject to final analysis online).
When a BT is confirmed, you’ll see a BT badge under Activity details.
Tapping that will generate a special BT report (Strava upload instead of XFAI report). Example:
More examples here: Let’s See Your BREAKTHROUGHS! 
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To view your BT details (where MPA was exceeded or flatlined) select the Previous button below the Activity’s power chart. Example:
Reference – Breaking Through the Xert Way! – Xert