Corrections

1. Making the flammable block catch fire takes a long time (gamerule randomTickSpeed)

1. Has a different procedure for a block increase.

   1. Dig out 2 blocks horizontally, to the non-air block.

   2. Fill in the other end of the hole with lava

   3. Place the block, closing the tunnel.

2.  If you don't want to wait, set gamerule randomTickSpeed to 1000.

❌  Has the same effect and speed of the original procedure.