it is necessary for the aircraft to do so in order to take of or land;
The way I'd view it is that if you're landing IFR, 29(a) applies, so you can come down to whatever. As soon as you become VMC and you're not really on a published IAP, you can't really be IFR, therefore the VFR rules apply, notably the 500' rule. This is stated in
Without prejudice to the provisions of rule 5