PTJ potential project - Adjustable RMH

This is my personal dream for a RMH expert to come up with.

With my limited experience, it seems like any barrel style RMH design is a balance between fast heat and slow heat.  The barrel gives fast radiant heat and the mass gives slow heat.

If you have too much fast heat, you heat yourself out of the place before the mass gets warm.  If you have too little "fast heat" it takes forever to warm up if the structure was allowed to get cold.

How about a RMH that can adjust how much heat turns into fast vs slow heat?

Several ideas:
 - Telescoping barrel - The normal RMH barrel would be mostly covered with a thick cob layer.  A second barrel telescopes up out of it when you need more instant radiant heat.  This would clearly have issues with the telescoping action staying moveable and sealed.
  - Hefty clam shell - Build a normal RMH. Mount a thick metal shroud/clamshell behind it that can open to expose the barrel to the room or close to contain the barrel and its radiant heat.  By being thick metal, it would slow down and store that heat for a slower release.
  - Top lid - Cob the barrel mostly up the sides.  Mount a thick metal lid to a hinge at the top back of the barrel.  So that lid could sit on the barrel or tilt up like an open soup can.  For instance it could be a man hole cover.  Then you flop down the lid for slower heat and tilt it up to let the heat off the top of the barrel into the room.
  - Second barrel bypass - Have two separate barrels.  Cob the first one (with the riser in it) so it stores heat.  Have the second barrel next in line and exposed to the room for fast heat.  Have a bypass under that second barrel so you can let it heat up or not depending on your needs.
  - Top hat barrel - Have a normal barrel that is covered with cob on the sides.  Put a smaller barrel on top of it (directly or with two pipes leading up to it).  Have a slide gate that allows hot air up in to the second barrel or keeps it out.
  - Seven other ideas the actual experts come up with :)

One option would be to build a cob warming box/oven with several doors that covers the top and part of the sides of the barrels.  When you want quick  heat open all the doors.  When you want to put more heat into the mass you can close some or all the doors.

You could also use a fan to blow heat from the oven into the room.

J, your oven idea is close towhat I thought of, but mine was just a white oven in a masonry bell, with an insulated door.
Mike, your top hat design reminds me of one of Matt Walker's early outdoor cooking designs.

I wonder would passing a pipe through the inside of the bell be enough to create strong airflow via convection without a fan?