Have a big tax bill due.

The bill would be enough to get me the 10,000 MQM Miles Boost at $25k and a big chunk of the way towards a second 10,000 MQM Miles Boost at $50k.

Has anyone paid taxes with their SkyMiles Amex via officialpayments.com?

Any problems with Amex denying those transactions just for the regular SkyMiles or counting towards the Miles Boost thresholds?

Anyone pay with multiple charges because the credit limits didn't cover all the charges they needed to make?