I don't really think transcripts are necessary because it can be the way someone says something that creates a very strong impression on others, making it memorable in context with the matter/s at issue. When the witness said something were they emotional, blushing, smiling, repeating the same answer over and over to different questions as if bored or oppositional, hesitant, convincing - or not, etc. None of these things would be reflected in words on paper, and whatever system is used for transcribing, software or a stenographer, is not 100% reliable, so jurors notes will be by far the most relevant for them.
Take for example the incident with the lighting in the nursery. Jurors will have heard the designated nurse testifying that the light was off, it was dark except for lighting from the corridor, LL said the baby looked pale from the doorway, and the nurse put the light on because she couldn't see the baby. They will have her nursing notes in evidence, which stated at the time that she put the light on to look at the baby. They will have impressions about her testimony. Jurors will have also heard LL's police interviews read out in court, when she said the light was off and maybe she spotted her paleness because she was more experienced than Ashleigh. They will have heard LL testifying under direct examination that the nursery light is never off it's just dimmed, so that they can always see the babies, and they will have their impressions of that. And they will have heard LL being cross-examined on her defence statement which was that they turned the lighting up before she noticed the paleness, and answering that she doesn't know if the lights were off and had just approached the nursery doorway from the lit corridor. The jurors will have probably formed opinions already on what they believe happened, without needing to see LL's testimony transcribed. And the arguments will be made again by defence and prosecution in closing, and a summary of all the evidence they've heard about that incident will be given again by the judge. If any jurors came away with conflicting impressions of what happened, they then deliberate over this, and there are 12 people who have been witness to all of this to make the task easier. IMO
I think worrying about the jurors' memories is not really an issue. JMO