Will be interesting to see how those whitewalls go, all experiences of whitewalls ive done (in very similar fashion) do go yellowish after a month or so (ive also used lumbersider, white etch, and arcrylic) never have issues of cracking or falling off, ive used a similar process, but i have used normal painters masking tape you can curve it no problem at all just need about 6 to 12 inch excess to be able to curve, and i used a ppg product which is a etch for plastic/rubberised bumbers and moulds before painting and seems to work very well. And the key to minimal yellowing is using older tyres do not do this on newer tyres.
But I do emphasize to try this on tyres you dont care about as if it fails it is impossible to clean up later.
Just my 2cents