Possibly not a real solution but might offer an alternative train of thought but...

Premiere Pro (v2) has the ability to parameterise a template title and then automatically build all required instances of it - kind of like a 'mail merge' function. Is that type of route open to you at all?

or...

maybe you could take a video clip of numbers counting (if you have one) and key frame it's speed (i.e. as a series of pauses)

Not my app so apologies if these thoughts are of no help.

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