RZF stacking with Prime Time player is an enticing combination, but for any 1 player it is extremely unlikely that even 1 situation will occur per game where those could kick in together. Maybe if you force starters in the red zone or something you could get a few situations where it comes into effect, but when you tally how often a pass is thrown in the endzone to your man it is fairly rare.
Considering the Football Genius is active 100% of plays both passing & rushing and you're bound to face more third down situations where both 3DS or clutch activate these become a little more appealing imo.
That being said, I think there is some merit to all LBs, CBs, and safeties putting 5 or so points in PTP so that your defense will always get a small bonus to passes in the end-zone regardless of whether it is to a wideout or the TE being covered by the LB. Similar to how teams use the 2 pts in MS strategy I think as a team these VAs can be more useful.