Just now we have noticed a change in the max XM possible.
| Level | Old Max | New Max |
|---|---|---|
| L9 | 10,900 | 11,500 |
| L10 | 11,700 | 13,000 |
| L11 | 12,400 | 14,500 |
| L12 | 13,000 | 16,000 |
| L13 | 13,500 | 17,500 |
| L14 | 13,900 | 19,000 |
| L15 | 14,200 | 20,500 |
| L16 | 14,400 | 22,000 |
So every level after 8 increases at a rate of 1,500XM.
In addition to this, the cost of boost recharging has changed from 10,000 XM to 15,000 XM. It seems boost recharge is reserved for higher level players. It appears that 15,000 XM is the max amount that a boost recharge can use. It seems to range between 5,000 XM and 15,000 XM (at 1k intervals) depending on how much XM you currently have.
Thanks to Jordan for the chart!