there is some truth to it for more blades better
fewer blades (3 bladed) need higher rpm to run
For same airflow the 5 blade can run slower rpm compared to 4 bladed
case in point comparing these
https://www.kdk.com.my/product/k14xz-pbr/
vs
https://www.kdk.com.my/product/k14yz-pbr/

the 4 bladed is 102-196rpm
the 5 bladed is 95-183rpm

power consumption about the same coz more blade heavier to turn.

TLDR, any 54-56-60in about same airflow one lah whether it has 3-4-5 blades. Its more on aesthetic choice.

60in regulator with 3 blade, because of higher angular velocity of a bigger diameter produces the most wind at lowest cost, lowest maintenance cos the regulator house the capacitors and RM32 every decade to replace *very user servicable too*. whereas remote fan all on PCB and replacement need some work.

However for remote fan go for the KDK Vtouch or KDK Sensa, likewise for Pana also look at RM400 series up (Nami)
do not get the Bayoo series. many lemon.
Rm300 one if new model OK. as this is the cheapest remote series-new model new dies ok the plastic still in tolerance. after  many years of use the die lose tolerance and a lot of funny stuff happen as QC is close two eyes on the cheap series.
Try contacting Alpha directly? IIRC, things from Alpha, Joven they do sell spare parts (even for their WH)..