Looks like I'll be walking alone (in this thread) for awhile thus I'm going to tell you a little story.
Back in the 2012, I've just discovered this forum (and @Digit blog for that matter) and I was very impressed by the possibilities of fully controlling a HVAC system (Remeha boiler). As I was in the market for a new boiler, I've searched the local dealers and finally bought a Remeha Quinta Pro 45. As a side note, this model is different from the old "Quinta" one, being an updated version (similar to Calenta/Avanta).
Well, I did't have enough time (at that time) to fulfill my dream (remote controlling my boiler over the internet). You may notice my first post back in that period when I was just testing the Recom software and played with the RS232 to TTL interface.
There were some professional changes in my life during that period too hence I was forced to abort this project. The Remeha walked alone through these years with an old "blind" (aka on/off) thermostat but it survived.

Now I finally have the time to finish my project (along with an entire home automation diy system) so here I am, asking for guidance. After all, you guys owe me some help for the decision I've made four years ago! (j/k)
I've read a lot of threads on this matter but, like I've just said, I saw that everyone is using an OT thermostat and a commercially/diy OT gateway interface to do the job. I must confes that I was a little bit disappointed to find that things didn't changed a lot in the mean time and the (easier to build) RS232 interface seems an obsolete and useless option.
So I'm asking it again: is this interface a "read only" one? At least, I want to know if it worth trying to further investigate, based on your past experience.
The way I saw it, it supposed to be just a TTL clone of that Manchester coded OpenTherm interface (the former being more convenient for master/slave operations). Also, the OT port allow a 2-wire communication and a compatible interface with the dumb on/off thermostats while RS232 it's a 3-wire interface. But aren't those commands similar when using RS232 or OT (Manchester) interfaces?
Btw, I only have linux all around me for years thus I could not test/sniff Recom software for now (though a virtual machine could be an option).
Sorry for this long message but I just wanted to explain the time gap (2012 - 2016) between my posts. Thank you once again for your time.