Does Greek present tense “continuous lifestyle” always mean that x always does y or can it mean x regularly does y for a specified period and stops?

The question is about Grammatical aspect in Koine Greek, as OP clarified. That’s OK, the behaviour of aspect in Greek has not essentially changed since antiquity. In fact, not that I’ve checked, but I’m struggling to think where it’s changed at all.

• x always does y is either continuous aspect (unbroken), or habitual aspect (does it all the time)
• x regularly does y for a specified period [and stops] is iterative aspect.
• Continuous, habitual and iterative aspect are all subclasses of imperfective aspect. They contrast with perfective aspect, which emphasises that the action is complete.
• The “and stops” can make the action perfective; but if it’s happening in the present tense, the “and stops” is in the future, so it would be irrelevant.
• The Greek present indicative (and future, for the inflected tense) does not differentiate between perfective and imperfective at all. τύπτω means “I am hitting” or “I hit (usually)” or “I hit (one-off)”
• Greek distinguishes imperfective and perfective in the past, and in non-indicative presents. ἔτυπτον “I was hitting” vs ἔτυψα “I did hit”; ἐλήλυθον ἵνα τύπτω “I came to be hitting” vs ἐλήλυθον ἵνα τύψω “I came to hit (once)”.
• Koine Greek, it seems, also made this distinction in the present, with auxiliary formations of the form εἰμί τύπτων “I.am hitting”
• None of these distinctions differentiate continuous, habitual and iterative aspect. They’re all expressed in the same way in Greek, whatever the tense.