Drozd/ERA

[Vespers War]

The active protection systems likely wouldn't be worth it. Drozd only protected a 60-degree arc to the front of the turret, had a roughly 50% chance of intercept (it had difficulty tracking the altitude of incoming projectiles, making it less useful against top-attack ATGMs like Tank Breaker/Javelin), and had just 8 rockets. Arena has a much better arc (around 300 degrees) and more counter-rockets (20-26 depending on hull), but still only around a 55% chance of intercepting an incoming rocket.

Reverse-engineering ERA might be more fruitful. From a game perspective, Kontakt-5 on a T-72B would make the front glacis immune to 120mm L/44 ammunition as long as the blocks lasted, with an armor value of 248 vs HEAT and 208 vs KE. The turret front would only be vulnerable to KE at short range and immune to HEAT. Sides and rear would still be vulnerable, but less so. It's much better than Blazer, but I'm not sure how Super Blazer compared.