Ah, the topic of trucks.....Just don't wheel a D40 very hard. The front axle is an aluminum R180 and stresses will crack them like an egg. When they switched over from the D22 platform, they added 85HP and put in the smallest axles they could find. The D44 rear seems to hold up OK (unlike the Titan axles which have had tons of failures with guys who actually use the trucks to tow the rated amount). This would only be due to the fact it's a smaller, somewhat lighter truck that typically isn't used for heavy towing.
Frontiers are still OK trucks but they don't compete with the Tacoma in resale. Not even close. You'd have to get a smoking deal on one to make the Frontier purchase worth while, and then plan to drive the wheels off it. If you are a trader inner, the Frontier is a terrible deal compared to a Taco, no matter how good the truck is.
I too wish the solid front axle would come back. I've SAS'd a few D22s myself, and we've got literally hundreds of them over on N4W that have been SAS'd over the years. You'd think manufacturers would notice this. Jeep is at last making a Wrangler pickup in 2019 that satisfies almost all my wildest dreams about what an OEM should do. The problem with it is that it's still a fricking Jeep.
Toyota got the mini truck exactly right from 1979-1985. It's the gold standard. Underpowered but otherwise basically bulletproof and simple as they should be.