Anyone get their Cameroon visa's in these locations recently?

Is it possible to obtain on the same day? or is next day, in morning or afternoon?

Important to be efficient for the following reasons:
(1) my visa is only for 7 days [i will ask for mre days at border]
(2) Calabar large boat to Cameroon departs only T & F at 09:00h, and what if there is a problem with the boat or weather that day?
For example, applying for visa in Calabar on Monday is no good if it's a next day in the afternoon processing time.

What is cost of double/multiple entry?
Thinking to make a circular route Cameroon->Chad->CAR->Cameroon then to Gabon... but maybe "border-hop" from
Cameroon to Chad, then Cameroon to CAR, then Cameroon to EquatGuinea

On road map, there are larger roads in the south/center of Cameroon to Chad and CAR, but are these the best conditioned roads?
For example the road from Cameroon to capital of Chad might be in better condition, but that's a long way to drive up north in Cameroon just to cross to Chad.

Note my original idea (back in Jan 2011 & Jan 2013) was to go north-east Nigera , get a laissez-passer across Cameroon to get to Chad, but of course with the north-east Nigeria kidnappings and killings, i ain;t goin' there.