All calculations were done using a full, 10 slot bitcoin farm (17 hours for one btc) and no solar because I feel like that's more common than a full 50 slot with solar and it actually doesn't matter, the costs that matter are everything else. Also, I used 700k as the price per bitcoin, even though yes it is higher than that right now I know, It was just a nice round number, and again the price of BTC doesn't actually matter for these calculations what matters is the price of fuel and materials to make the mag cases in the level 3 lavatory.
Short answer: not really, but if you can get the materials to craft the mag cases cheaper than the prices I listed, go for it. (also it's absolutely worth if all you care about is leveling your crafting skill. you make profit either way, it's just a matter of how much. It's also good if you can get the blue tanks for under like 180k, that would be value.)
Longer answer: One metal fuel can will get you 24 hours of fuel, which nets you 1.4 bitcoin with a full 10 slot farm, or, 980,000 rubles. Your cost of entry here is 150k, the metal fuel can price from jager. Your trade ratio here is 1 ruble : 6.5 rubles.
One blue fuel tank will get you 14 hours of fuel, or .82 BTC worth 575,000 rubles at an entry cost of about 180,000 rubles. This is obviously worse- to get 1.64 bitcoin worth about 1.15 million rubles, you'd have to pay about 360k for fuel (2 blue tanks) instead of just 150k for a metal can. But, it doesn't seem that bad at face value. Obviously 360k for 1,150,000 rubles is still a good trade, but at a trade ratio of 1 ruble : 3.2 rubles, it is not nearly as good.
The real question though, is does the magazine case make up for this loss of profit?
Here are the prices of the materials to make the mag case excluding the fuel tanks: 40k for one metal cutting scissors, 100k~ for 3 bolts, and 50k~ for 3 screw nuts. So, our cost to make the case is about 190k, and it will sell for 400k minus a market fee of 35k, so 375k. Assuming the fuel is free due to the bitcoin, you're making about 185k per case, and make one case for each two blue fuel cans. Effectively all this does is subtract 92,500 rubles from the purchase price of each blue fuel can- so let's do the math again assuming a purchase price of 87,500 and see if it's value.
So, we'll multiple 87,500 by 1.7 to get 24 hours of fuel, which is about 148,000 rubles. This gives you a ruble ratio of 1 ruble : 6.6 rubles, effectively identical to the initial investment of just buying metal fuel tanks.
The only other variable I really see as maybe being problematic here is the cost of the materials to make the case. Like I said, I assumed a cost of about 40k for one metal cutting scissors, 33,333×3 for the three bolts you need, and 16,000×3 for the three screw nuts you need. IF you can get these cheaper than that price or find them in raid, it is probably worth it to craft the mag boxes.
If you see that I did my math wrong anywhere or left out any variables please let me know, I am terrible at math.