Check out the BP Mods x Dovpo Pioneer DL Extension Pack unlocking direct lung capabilities, offering a larger conical chamber and 510 airflow pin pathways.
BP Mods x Dovpo PIONEER DL Extension Pack Features:
Direct Lung Extensions Kit
Large Conical Flavor Chamber
2 510 Threaded Airflow Pins
Widebore 510 Drip Tip
Available in Black, Stainless Steel
1 DL Extension
2 510 Airflow Pins
1 510 Widebore Drip Tip
1 O-Rings Pack
I set up my pioneer with the dl kit, the smaller air pin from the kit, and the mtl mouthpiece. I'm probably weird, but the airflow is great now and I can do either mtl or restricted dl just the way I like it.