slowly, this works:

---- action_exec: start -----
EVENT: 0105d(267)
Tapping: Start(Press tap key).
TAPPING_KEY=0105d(267):0
processed: 0105d(267):0

Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping

---- action_exec: start -----
EVENT: 0402d(363)
waiting_buffer_enq: { [7]=0402d(363):0  }
---- action_exec: process waiting_buffer -----

Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key presed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressedbefore tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key presed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressedbefore tapping
Tapping: End. Timeout. Not tap(0): FFFFu(449)
ACTION: ACT_LAYER_TAP[3:F1] layer_state: 00000000(0) default_layer_state: 00000000(0)
layer_state: 00000000(0) to 00000008(3)
TAPPING_KEY=0000u(0):0
ACTION: ACT_LMODS[2:21] layer_state: 00000008(3) default_layer_state: 00000000(0)
processed: waiting_buffer[7] = 0402d(363):0

$
---- action_exec: start -----
EVENT: 0402u(503)
ACTION: ACT_LMODS[2:21] layer_state: 00000008(3) default_layer_state: 00000000(0)
processed: 0402u(503):0


---- action_exec: start -----
EVENT: 0105u(523)
ACTION: ACT_LAYER_TAP[3:F1] layer_state: 00000008(3) default_layer_state: 00000000(0)
layer_state: 00000008(3) to 00000000(0)
processed: 0105u(523):0


==========================================================================================

fast, this leaves shift stuck:

---- action_exec: start -----
EVENT: 0105d(9313)
Tapping: Start(Press tap key).
TAPPING_KEY=0105d(9313):0
processed: 0105d(9313):0

Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping

---- action_exec: start -----
EVENT: 0402d(9353)
waiting_buffer_enq: { [0]=0402d(9353):0  }
---- action_exec: process waiting_buffer -----

Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping
Tapping: release a key pressed before tapping

---- action_exec: start -----
EVENT: 0105u(9377)
Tapping: First tap(0->1).
TAPPING_KEY=0105d(9313):1-
ACTION: ACT_LAYER_TAP[3:F1] layer_state: 00000000(0) default_layer_state: 00000000(0)
layer_state: 00000000(0) to 00000008(3)
waiting_buffer_enq: { [0]=0402d(9353):0  [1]=0105u(9377):1- }
---- action_exec: process waiting_buffer -----
Tapping: key event while last tap(>0).
ACTION: ACT_LMODS[2:21] layer_state: 00000008(3) default_layer_state: 00000000(0)
processed: waiting_buffer[0] = 0402d(9353):0

Tapping: Tap release(1)
ACTION: ACT_LAYER_TAP[3:F1] layer_state: 00000008(3) default_layer_state: 00000000(0)
layer_state: 00000008(3) to 00000000(0)
TAPPING_KEY=0105u(9377):1-
processed: waiting_buffer[1] = 0105u(9377):1-



---- action_exec: start -----
EVENT: 0402u(9407)
Tapping: other key just after tap.
ACTION: ACT_LMODS[0:09] layer_state: 00000000(0) default_layer_state: 00000000(0)
processed: 0402u(9407):0

$Tapping: End(Timeout after releasing last tap): FFFFu(9557)
TAPPING_KEY=0000u(0):0