Presently, we do not recommend using Tiny Tim for WFC3 data as it relies on outdated optical models (WFC3 ISR 2008-14, published before WFC3 was installed). As an example, WFC3 ISR 2014-10 found significant errors in the WFC3/IR Tiny Tim model. Our team has focused recent efforts on building empirical PSFs and a database of observed PSFs.