Fair warning to readers who may be afflicted with bibliophobia
A fellow Canadian expat applied for his new PP early December through the Canadian consulate office in HCMC. He qualified for the streamlined application, as his current PP was neither lost, damaged, nor expired. The reason for his requiring a new PP was that he had run out of pages.
The quoted turn-around was 15 work days from the date the application was received. His new PP was delivered to him, via courier, 5 days after the consulate office received his application. Very nice work by the staff there. His old passport was returned to him, with the top right corners cut off. (he was rather delighted that the new PP's "Issued at" line states, "Ho Chi Minh City" 
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So, with his newly minted eVisa in hand (the new eVisa showed his new PP #) he went to the border to do his visa run.
And this is where his education in new passport issuance commenced.
He presented his new PP to the officials at the Vietnam departure desk. He told me that they looked it over, and told him he had to go to the immigration/police in T.P. Kien Giang as there was no "Entry Stamp" in the new PP, hence he could not leave without documentation of his entry. He was also told that at all VN land border crossings, the border is manned by the military, not by immigration officers. Apparently, only the airports are manned by immigration/police. At the land crossings, the military are not authorized to make changes to immigration protocol.
No problem, he thought, as he had the old PP with him which had the "Entry Stamp". Nope, no good he was told, as the passport holding the entry stamp was now cancelled/invalid.
So, off he goes to T.P. Kien Giang, which took about 2 hours by taxi. Thinking that if he spent an hour at the immigration office there, and accounting for another 2 hours taxi ride back to the border, he'd still have plenty of time to cross into Cambodia and return.
Not so. Because the new PP required a new entry stamp, Kien Giang instructed him to go to HCM immigration offices. At this point he was not a happy camper. HCM was about a 4 hour sleeper-bus ride from Kien Giang, and by that time HCM's immigration offices would be closed. He arrived in HCM at ~11:00pm, got a hotel, and caught some sleep.
Early next morning he visited immigration in D1. Immigration advised him that because he was now in over-stay status, that he must exit VN by air. By air, and by air only. An over-stay visitor, he was told, could not exit via a land border crossing. He was instructed to go to Tan Son Nhat Airport, where immigration would advise him of the penalty for the over-stay. At both the immigration office in D1, and at the airport, the officials seemed unsympathetic to his reason for over-staying.
One day over-stay penalty was 1,250,000 VND.
Because his new eVisa stated his "Entry Point" as Ha Tien (Kampot, Cambodia border crossing), he opted to fly to Phnom Penh, at a cost of 5,850,000 VND.
In total, his border run took three days.
Costs were, including hotels (HCM and Phnom Penh), taxi and bus fares, train ticket from Phnom Phen to Kampot, two ferry rides, over-stay penalty etc etc etc was ~12,000,000 VND.
Should any expats/travelers/tourists find that they are requiring a new passport whilst abroad and who wish to avoid my fellow expat's experience, please ensure that any stamps which had been entered in your old passport are transferred to your new passport by visiting a VN immigration office prior to finding oneself in an over-stay position.
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