Hi Sian,
I don't know whether this will help, because I am not a big fan of counting things unless there is a really strong reason, and even then, only for as along as it is necessary and not a moment longer.
I would suggest you think about fidelity in a different way. More in terms of trying to work with your team to maximise the potential of the interventions. So, for example, you could take time to talk to the team about selected soft words posters and ask them to share examples of how they've used or applied them, successfully or unsuccessfully. This gives everyone a reminder so that the techniques is accessible to them to choose when they need to - you can't choose what you don't remember. It also harnesses the expertise of your team to sharpen and improve the content of the intervention. For talk down, you may want to use it as a debriefing tool - what was tried, what was not tried, etc.
You could think of similar angles on each of the interventions that ensures they get used and therefore fidelity increases, without relying on counting. Instead rely on your team, make sure they know you are relying on them, and they will come up with the goods, as it were.
Maybe others will have other suggestions.
Good luck,
Len
PS I showed some pictures of your team and their work at the MHND&LF meeting yesterday!