Not really.
It depends on the:
a) style of ERA placement
b) sensitivity of explosive used in ERA tiles
If we speak of T-80BVM,
a) ERA is fitted in brow-like manner, there are upper and lower angled tiles. If one ERA explodes, say, lower one, the explosion has a chance to trigger adjacent tiles, that would result in a bigger boom, leading to enitre “cheekbone” loosing ERA. Worth mentioning that K-5 does not use the principle of “focused” explosion, thus collateral damage around the tile explosion is higher.
b) I can’t find what kind of explosive is used in K-5, but I’d guess it would be better than TNT, however sensitivity of explosive also plays great role. Shockwave might also trigger explosive, thus leading to a chain “boom” across several points.
For BM Oplot,
a) ERA is fitted in different manner on turret and hull sides. The principle of Nizh is that it has “focused” explosion, e.g. it uses hollow-charge effect to slice projectiles. It doesn’t mean it offers no collateral damage, but most energy is focused “upwards”, thus ERA blocks on turret cheeks would not be fused because one was hit but because the one bellow it might “slice” the block above it, leading to chain damage. Worth noting that casing for Nizh on turret is also different, as these “slots” are also made of HHRHA, and offer a certain degree of protection to adjacent ERA blocks. On hull sides, if the back layer is triggered, it will slice the front ones too. The only problem is that devs wrongly combined some ERA tiles on turret, as if 2x tiles placed on top of each other with barely any separation give 140mm KE protection, even though a single tile gives the same result.
b) Nizh ERA uses hexogen (RDX), which is relatively insensetive, but the boom from such tile is still big, thus requires some extra casing. In fact, if you look at those trials of Duplet on hull front, there was a test of tandem hollow-charge projectile from RPG, and it only fused one lining of Duplet ERA, with the adjacent tiles being okay. But still, RDX is not completely insensitive, thus explosion of several tiles of Nizh/Duplet is also possible.
But the game does not represent chain ERA explosion in its entirety. If it did so, the enitrety of K-1/5 would be gone from UFP/sides/turret even from explosion of one tile, like it mostly does irl, but fortunately, we do not have such mechanic, so it is up to devs to decide what parts of ERA shall explode due to collateral damage or not.
