The Tial flange means that you have to buy Tial clamp and o-ring too, because Synapse doesn't supply this. It is assumed that you already have a Tial BOV. If you have the option to have your UICP mfg put in your choice of flanges, see if you can get them to put in either the OEM style, or an HKS. Yes, the C-Clip is a pain with the HKS, but it is probably much cheaper to buy the C-Clip and o-ring.
Or, just tell your UICP mfg to contact us and we'll supply them with flanges.
Please check out this thread if you are tracking your car. We spend lots of time on R&D, and these are some basic findings to help you, without you spending more money:
DV Flutter: Synchronic BOV perspective