Couldn't be further from BIAB!
Went:
Mash in at 38c strike - 35c rest for 15 minutes
Infusion to bring it to 50c protein rest
First thick decoction (1.5kg grain, no extra liquid) - raise to 65 for 15 then boil 20 minutes. Add back in to mash which had dropped to 45c
Raised it to 55c - D'oh
Infusion of more hot hot water and trying to use 1.4kw element to raise temp and stir but too slow so removed thin decoction.
Brought 'decoction' to boil and poured back in - hit main rest temp of 62c...
Removed 'second planned' (aka 'third' decoction) - 1/3 thin mash - and brought to boil, boiled 20 minutes and added back in to tun - raising mash to only 68c!
So FOURTH decoction taken off and brought to boiling point, 2 minute bopil then added back in to hit 72c saccharification.
15 minute rest... End of 4 hour mashing process
Recirc, run off and fly sparge...
90 minute boil with 60g tettnang
50g Tettnang + whirlfoc + chiller in at 15 minutes.
Crash cooling - actually quick (water temp was 6c so got it down to 13c in 25 minutes

Left to settle, run off into fermenter and pitched 2l starter of WLP920 Old Bavarian Lager - now in the cellar at a nice stable 9-10c and fermenting away.
MISSION - but fun, wort tasted gorgeous and malty with nice smooth tettnang bitterness. Methinks you'll like this one (and the schwartzbier too)
Steve