Will a Flipsky FSESC4.20 50A Controller Work with Unknown Motor?

Hello all, new member here.  I have an electric ATV (Venom E-Grizzly) for which I'd like to add a smoother, quieter controller.  The Flipsky unit is available locally and appears to be capable enough so it looks like it might be suitable.  However, I have no info available on the ATV motor other than the vendor claims its a 3,000 W (there are no markings on it al all).  The controller (also of unknown manufacturer) is rated at 1,500 W.  I have sent the manufacturer of the ATV (Yongkang Eagle Motor Co) a request for info but I not received a reply and doubt I will get anything useful.

Anyhow, since I have no detailed motor data, I am hoping the VESC wizard will work.  I have taken it as far as I can without having a controller connected and see that it gives a choice of motors sort of rated from small to large but no wattage figures are given.  Am I right in assuming that the "Large Outrunner" option would be the best choice (the motor I have is quite large - about 8" long and 6" diameter and, as mentioned, supposedly 3,000 W)?

The battery info I have (lead acid, 48V (Battery Cells Series = 24?) and capacity of 20Ah.  I can also figure out the Gear Ratio easily enough.

The ATV throttle is the Hall type with a voltage output between about 1.2 and 4.8V.  If required, I can interface it with a micro processor to produce a suitable PWM output.  The Flipsky accepts PWM but I'm not sure if it takes analog input as well(?).

Any help or suggestions would be much appreciated...