I lean towards Shimenawa just because one won't always be triggering reactions with Hu Tao because there is no point if wasting a burst when the fight is almost over.

For the record I do 40k CA with shim (raw) but only 28k with CWoF (raw) despite both sets having similar stats.

Her burst with CWoF is only about 68k. Hence, shim is a lot better in my opinion.

For vape both have similar numbers, 72k with Shim and 68k with CWoF

That number, is that the normal attack + charged attack? (N1C?)

No. Just the C. N1 is about 12k raw with shim and 7.5k with CWoF

Do you have a Staff of Homa then?

Yes. R1 dw