Georgia - sorry i totally missed coming back to this thread when i first saw it and meant to offer some insights where i could....
just read through everything and thought i would mention a few things (my 2 cents
as Liv was such good spirited training for me
1. in your windown i personally would make it more low key at that age. i think most spiriteds really don't want 2-3 songs etc as you noted it feels like "playing" to them instead of winding down. for Liv, seriously our wind down was low key time at the end of A time, nappy change, swaddle or sleep bag, turn out light and hold her for just long enough to sing 1 verse of rocka bye baby really softly and then put her to bed. she would then blow off steam and self settle (at 5 mo i am talking about - earlier months there was LOTS of shh/pat going on)
2. 6 mo is a major growth spurt for most babies so i imagine if she is waking in the night again and you think she might be hungry i would feed and then resettle
3. you are spot on about things changing constantly - i found every month we would get in a groove and then it would change again. i think that was when her A times started increasing. at 5 mo we moved up to 1hr 40-2hrs and then at 6 mo 2hrs + and so on
4. i highly recommend having a shorter A time for 1st cycle for spiriteds with no cues. i think it is a real extension of night sleep and if you can catch them early enough they will have a decent first nap and this reduces the chances of overtiredness setting in for the rest of the day (with you battling to get out of the cycle)
and i agree with "puffling" that as they get older they develop consistent cues (like poker "tells") that are unique to them. Liv gets hyper and as soon as she does something that others would crack up at we know she is crossing from fun loving to too tired to care.
i also highly recommend feeding in a quiet room in dim light if necessary to ensure full feeds and i HIGHLY recommend white noise machines to reduce distractions when they are trying to settle/sleep.
hope some of this was helpful. am cooking dinner and grabbed a few minutes - did not get to read other people's stories
but will be back tonight if possible.
BTW Georgia my mom also said everything i described is what she went through with me too