Hey Zsolan, thanks for your interest in the game and kind comments.
Will there ever be a print version? Unfortunately, probably not. This is a 'fun' hobby project for me and I have no interest in getting involved in the world of hawking sales or fulfilment. The beauty of the itch model is I can focus on the things I enjoy (designing) and just release content for free in .pdf format.
Can I get my own print version? Sure, there are online print options where you can upload your .pdf and get print copies made yourself. I'm based in the UK and use a company called Doxzoo which offers a website where I can upload the .pdf and get small quantities printed at a reasonable cost. Part of the reason for moving from one big rulebook to two smaller booklets was to make self-printing a more viable option. Each time I do a major release I will print a few books for my players.
The Heroes of Adventure rulebooks are a traditional 'letter' sized (8.5" x 11") for printing purposes. You could resize the print to A5 but the format will not use the full page (see screenshot below). Unless there was a huge demand for it then I'm unlikely to do it as it's a quite a bit of manual effort for me to resize and maintain two versions.
But.. I am toying with the idea of perhaps organising some form of Heroes of Adventure related Game Jam on Itch (perhaps putting out some templates and letting people create some stuff) when I go to final version 1 and perhaps getting a small batch of rule-books printed as prizes but not sure on the demand. This is a fairly niche area and my game sits in a very over-saturated market (i.e. a fantasy heartbreaker) so I'm not sure if there would actually be that much interest from people in participating.