Portable imposition software?

If I want to print my magazines on A3 spreads on regular printers, then fold them and staple stitch them manually (maybe even laminate the covers manually), what portable imposition software should I use?

Digital press is something nobody can afford (at least not for mass production of magazines) and the issue with offset press is that you must order a lot to get a good price, so that's not good for travelers, because then will I drag a trailer of mags after me?

So I might attempt to make handmade magazines with hand made artefacts on it (thus raising the price of it), but I would only make say 50 a time, and then when I sold it I print an other fifty.

Offset press is nice, but it's definitely not good for travelers, at least not until your magazine is officially out on the market, and you have your official points of sales.

But again then that doesn't work well for digital nomads, not at all.

I tried print ond demand, and believe it or not I got price tags like 50 dollars for a single magazine, shipped locally - so that's not for magazines. Maybe for occasional brochures, etc but certainly not for magazines in production.

So because print on demand fails for magazines, I want to make my own print on demand system, that I want to use for my magazine business.

The printing price would be still much higher than offset press, but it doesn't require the logistics and storage and big amounts printed, and that also costs money and it's a hassle and it's a very flexible solution, so this would be still viable.

Is there any any portable imposition software or I have to build up my PDF manually in Acrobat from individual InDesign Pages?

Can I do the imposition in InDesign after I am done, to just reshuffle the pages for A3 print?

Even if my mags will be later officially distributed, I still want print on demand instead of offset, both for my eventual sellers and for my customers. So I might need to build my own print on demand system.