No, layered TIFF won’t matter for scratch disk. Also, I recommend against saving templates as layered TIFF because TIFF has historically had problems with certain smart filters and occassionally layer style compatibility issues too. TIFF isn’t a Photoshop specific format and using it for layers can risk compatibility issues. Usually it’s OK…. but why risk it???

I’m assuming TIF was using because PSD are limited to 2GB (TIF is 4GB). However, PSB (Photoshop large format) is unlimited file size and always 100% compatible as it is an Adobe format. I would use PSB for files that are too large to be PSD, not TIF.