To add to it, the backstab mechanic is silly in the sense that it breaks immersion away from how battles should play out. I get it is turn based and this already requires a bit of suspending disbelief with realism in fights. But, the backstab implies that everyone just... stands there politely awaiting their turn. Not doing anything and allowing the opponent to do as they like. Like they feel they are in a real life game of chess and are not allowed to move when 1 other person at a time does their thing. In dnd it is implied everything happens all at once in a fight (The old games are a good example of this. Even nwn1 and 2 to an extent. Or Dragonage), the turnbased initiative situation is to make stuff managable and have a good overview and make stuff easier at a table.
I do not feel Real Time with Pause is a good option (turn based works better with 5e I think) but... to go with everything in a fight happening at once: It is implied you react to an opponent and are always considered to be facing them. It makes -sense- to do this. It is why in 3.x rules you can only sneak attack when flanking (And other situations), and you need advantage/someone engaged with the enemy to Sneak Attack in 5e even. Enemies are keeping their eyes on you.
Removing this backstab homebrew Larian rule, aside from making combat mechanically more engaging, would make sense immersion wise. It might feel more like a battle (even though it is turnbased, this is, again, for the sake of convenience for the player) rather than a group of people just LARPING and politely awaiting their turn.