61W charger for iPad Pro 2020 11-inch

If you supply a charger that is more powerful then what the device needs to charge, it’s only to use the amount that it can use and basically just not use the charger to it’s full capacity. For example if you use an 18W charger from the iPad to charge say an iPhone it will only charge the iPhone at the most powerful charge that the phone can use. It’s not going to harm the device that you plug it into

Should be no problem.

iPad will only charge at its max fast charging rate and will NOT use all of the wattage from that Mac Pro charger.

Should be fine.

Best of Luck to You!

Yes.

As the MacBook Pro charger is USB-PD compliant, your iPad will charge at its maximum supported rate - this being PD Profile 2 (12V @1.5A = 18W).