I have not heard the term "Orthoprax" in a few years, though for a while it was popular and perhaps trendy. I think, if I remember correctly, the descriptor "Orthoprax", at least when used in reference to the frum community, referred to people who were Orthodox Jews and continued to appear so and have stayed part of the frum community both socially and in appearance, but in private they do not practice religion, or they do but to a lesser degree than they used to and than what is normally expected in a frum community.

According to Kikar, a question was asked to the "gedolei poskim" recently regarding people who are Orthoprax, though I doubt this term was used. The question posed was:
what is the status of people who are no longer frum but they still dress like Haredim though in private, among others in the same category, they desecrate the shabbos - if they would send a Whatsapp message in their own group would that classify such a person as a mechalel shabbos bfarhesya and turn the wine they touch into yayin nesech?

Rav Mordechai Gross responded that if the Whatsapp group contains tens of people, that would be enough to consider him a mechalel shabbos bfarhesya, but if there were only 5 people in the group, even though they will pass along the message or let others know about this person, then he would not be considered a mechalel shabbos bfarhesya.

 Rav Nussboim (I am not familiar with who this is) responded similarly saying that if he sent the message in such a group he would be considered a mechalel shabbos bfarhesya, but if he sent it to individuals in a way that each thought he was the only one to receive it, then this fellow would not be considered a mechalel shabbos bfarhesya.

A different Rabbi Gross (with whom I am also not familiar) responded a bit differently. He said that if everyone in the group keeps the content of the group private and they do not publicize their chilul shabbos, and nobody but they know about it, then these people would not be considered mechalelei shabbos bfarhesya.

I find each answer interesting, each for its approach. And, more so, I find the fact that they are dealing with the issue at all to be particularly interesting. I wonder if it being sent to the gedolei haposkim now implies that the Orthoprax community is now so significant that it is an issue that must be dealt with.

Also, being that the question was specifically about their chilul shabbos via whatsapp, and not in general chilul shabbos in front of other people, it must deal with the question of cellphone use on shabbos and what category of chilul shabbos it falls under - derabanan, deoraisa, etc.

And, mostly humorously, none of the responses included a comment about their use of whatsapp ans smartphones putting them in a worse category than the actual chilul shabbos