Based in Lagos flying the "said routes". Everything being said is correct. The suggested solutions are excellent "ideas".
Pesonnally, I try and wait when another aircraft is in the middle of a transmission with ATC. Cutting a guy off who is either asking a question or is getting a badly needed update on his/her clearance is not only rude, its self serving and confuses the ATC folks. Lets think about each other and act accordingly on the RT. Its like panic mode. Can't think of anything that critical that justifies chopping off someone else's RT time. Well maybe fuel short. Seems like everyone is racing "to be first". Kind of unprofessional at times.
Footnote: ATC, considering the equipment and limitations, does a pretty good job. Mistakes are made, but overall its 1950 environment and the ATC staff deals with it, usually with a single controler. Controlers in the US and EU would go balistic in the RT environment. Never hear any Nigerian ATC personnel screaming at someone who is "cutting in", they just deal with it. Now I know why god invented TCAS/ACAS. TIA.