The Yankee Hill Machine Todd Jarrett Handguard uses proprietary heat vents that are not designed to accept rails. There is a small portion of 4 piece picatinny at the front of the handguard however.
The Yankee Hill Machine Todd Jarrett Handguard 12.585 Inch Black YHM-5008-TJ might work with the Pantheon Arms Dolos Take-Down Kit For AR-15. However this particular model of handguard from YHM is not listed as being compatible. I recommend contacting Pantheon Arms to confirm compatibility.
The Yankee Hill Machine Todd Jarrett Handguard 12.585 Inch Black YHM-5008-TJ is compatible with the Dolos/Prometheus lock collar.
1.75 ID 2.43 OD
As long as you have a low profile gas block, this should fit your S&W M&P15 regardless of gas length. If you have a railed gas block or the A2 sight post gas block, this will be too long as those will not fit under the handguard.