I would assume so. Regardless, you probably shouldn't try this too often with AmEx.

No tax is added to the $59

I have recently used both the $44 and $59.
Both worked, one on Amex Plat other on Hilton Aspire, both of which in last 2-3 weeks.
Purchased on a laptop

did the credit trigger? Thanks!

You should be able to and get credit just like the first purchased. I planned on using the remaining amount from my Aspire for 2nd flight.

Problem is, it has been 5 days and neither my mileage booster nor my award travel fee were reimbursed by Amex. Starting to get a little worried :(

11/13: Purchased two $99 roundtrip fares separately for $99 each. Used $50 GC for each of them and charged 2 x $49 to Aspire.
11/15: 2 x $49 purchases on Aspire coded as "Additional Collection"
11/17: Meter moved
11/18: 2 x $49 credits posted

Bought a $260 round trip on 11/13 with a $50 gift card, was reimbursed $200 today. Also categorized as "additional collection"

I've got about $225 left in DL airline credit on my Aspire card for 2019. I have a trip planned for April that was booked using Skymiles and found out this week that it may need to be cancelled. DL Charges $150 per ticket (2 roundtrip tickets, so $300) to reimburse the miles (about 45,000 miles total in this case). Will the $300 cancellation fee trigger the remaining $225 of credit I have left? Anyone have experience? I for sure want to use the credit before the end of 2019, so if I get confirmation that I need to cancel the trip (or maybe change..for same cost) I plan to do so by the end of the year. The other option is possibly using a gift card and 2019 credit to buy a different future flight. I could then use 2020 credit for April trip cancellation.

Kind of off-topic, but I thought award travel on airlines were fully refundable as long as you cancelled within a certain window? Dang, are all airlines being so draconian about award cancellation?

Mileage booster, baggage fees and in-flight food all reimbursed within 2-3 business days of the charge posting.

The last one to offer that was Alaska. Now there is a fee to cancel everywhere. BA and Virgin Atlantic are more lenient in the sense that if the taxes paid are less than the cancellation fee, they keep the taxes you paid and don't charge a cancellation fee.

It is on Delta as long it's at least 72 hours before departure time for PM and DM's.

Correct, I'm not PM or DM. So my question still stands. Anyone have experience with this triggering the reimbursement? I have read through the T&Cs and it does not list change/cancellation fees as being excluded. I would think it should qualify.

The airline fee credit is intended for things like change/cancellation fees. If it doesn't automatically credit, this would be something that is actually legitimate to call Amex about and have them push it through.