First of all defensive players need to understand that there are no known mass produced oversize blades in table tennis.
If you want one you need to have it custom made.
Second issue > The very definition of an an oversized blade. A 165 mm x 160 mm blade is NOT an oversized blade. It is a semi-large blade.
For a blade to be remotely useful for a defender in the 40+ plastic ball ONLY era (if that is possible) , you need a large blade. A large blade is like 170 mm height x 170 mm in width. And no, it cannot be 170 mm in height but only 165 mm in width. I don't know where this nonsense about width being lss than height came about especially for a defensive blade, You need maximum possible dwell time and you need maximum width.
If you are a classic defender who mostly chops from both sides . you may be able to use a symmetric blade.
But if you are modern defender , (whether it is with short pips or spinny inverted on forehand) , you need an asymmetric blade with possibly a slower dofter and very spinny backhand (for so called long pips on ITTF LARC, which are actually medium pips) and a faster forehand side.
The forehand should be ike ZLC if you are using short pips for flat hitting or ALC if you are using spinny inverted for looping.
The counter argument has been that the blade gets heavier. This may be partially true for some pros but for amateurs this is a dumb arugument. Because an amateur should be using an OX rubber on backhand(or at worst a very thin sponge) . Also if you are a chopper away from table, this is a non issue. Even if you are close to the table blocker larger blade with OX rubber can keep the blade light enough.
You should take a look at the racket of arguably the greatest woman player in history Angelica Rozeanu and many other defensive oriented top players used large blades. I will post pictures later.
Pro defenders (especially men) need thick sponge to aborb the heavy top spins of incoming loops by illegally boosted up loopers. Otherwise the ball will shoot off the wood if you are using OX rubber, especially those so called long pips on ITTF LARC.
But for an amateur this excessive top spin is not an issue for playing against loopers as high as 2300 USATT rating & defenders can (must) use OX rubbers for maximum control & spin variations. At low incoming top spins control is actually an issue if you use a sponge thicker than 0.3 mm. Amateurs should never be using sponge thicknesses like 1.5 mm or more. Even for attacking with long pips OX is far superior because of the minimal spin in your flat hits or the effect when you side swipe at lower speeds..