Let’s do the physics then. Since I don't know the effective mass of the MA505, let's take Halcro’s FR64s, which I believe has 20g effective mass. Then add an 8g headshell (e.g., Yamamoto boxwood), where most of the mass is quite far from the stylus and hence let’s guesstimate its contribution to the effective mass to be 6g. Then add a 6g cartridge like A&R P77, where again most of the mass is well towards the pivot and not right at the stylus, so we guesstimate its contribution to be about 5g. So now we’re at 31g total effective mass. Compliance is 20 and thus the resonance is 6.4Hz, which is fine. Even if we took the headshell & cartridge at full weight, we’d be at 6.1Hz, which is also fine. If you have a stable turntable & non-warped record, this should play fine.
Now switch a Koetsu Rosewood into the same headshell. Its weight is 9g and we can again guesstimate the contribution to be a bit lower at 7.5g, say. The compliance is 5 and thus the resonance is 12.5Hz, which is fine. Again, even if we take the headshell & cartridge at full weight, we’d be at 11.7Hz, which is again fine.
