What I can offer about jejenes...
First of all, San Blas has two faces: Winter when the winged crocodiles are active. And summer when they are far less active.
Jejenes thrive in salt water sand. Their big cousins love a mix of fresh water and salt water. Brenda does like the rest of the enramada owners -- she wets down the sand inside the enramada every morning with community piped fresh water. Our jejenes are a nuisance and not miniature versions of The Alien. They tickle feet and bare skin all the way to the knees. They bite but the effects are like 1/10,000 as profound as San Blas / Boca de Iguanas effects of drilling.
Even the very worst pea-size knobs that drive one crazy can be effectively treated with nothing more than water, a flame, and Q-Tips. Heat water to boiling, dab a Q-tip then apply it to the bite. Really bad bites require two applications. But the relief is 100% and the length of total relief is forever. Nothing else I have ever encountered will offer one single percent relief to that which this trick offers. Not even injected antihistamines do as good. Remember the words Total and Permanent relief. The dab of hot water does not harm the skin in the least.
The town of Sta Cruz to the south, made San Blas look like the Nixon library. The pungent odor of marijuana and Patchouli oil saturated this tiny village to the core. Ugly brown donut rings of cactus peyote were sold openly in the late 60's and 70's. Marijuana smoke similar to tobacco smoke makes me gag.
Another infestation was stumbled upon at Tenacatita. I spent one night at Sta Cruz then hauled A$S. At Tenacatita, it was mid-morning and I made a U-Turn and ended up at La Manzanilla.
Back then, camping amidst hippies was not an option. The PJF Policia Judicial Federal would descend on a campground and end up arresting everybody. Things would be settled later in jail. No thanks. When the PJF was around the mere presence of the magazine High Times, or a copy of Guns & Ammo would set the plain clothes PJF into high gear.
The PJF was dissolved more than 20 years ago. A step forward.
About 15 years ago the SCT "straightened" dozens of the worst curves between Tepic and Campostela. Nicer drive going south but northbound it is normal to run into a six cylinder diesel truck banging on 5 cylinders doing 17 mph. No way to pass.
In Tepic, the street with a hundred topes greeted the exit from Mex 200.
For me in a toad, Mex 15 had three or nine too many negatives. Hotels at 2-3 times the price of Mex 57-D, in the summer sweltering temperatures on 15, 15 gallons of fuel for the price of 18, too many cities with no periferico and punitive toll road prices. Cheaper to drive east 800 miles and enter at Eagle Pass.
Of course this omits places like San Carlos, Mazatlan and Puerto Vallarta. To each his own. To me any route any more is a commute.