It’s a very awkward non-solution to keeping him somewhat useful and a lot of his success relies on such a mechanic. Considering this is primarily an out of combat trick, it does not impact his fighting potential directly so they tolerate it.
I don’t really have an idea how the developers would compensate him for losing this, but there is a still a problem in how execution is possible only with a shift-queued command (closest comparison I have is Genji dashing outside from spawn area and still instantly mounting up with uninterrupted movement).
When images attack or Samuro attacks a hero they increase the duration of his images by 1 second but not above the 8 seconds baseline duration, but regardless the images disappear by default once the Heartstone finishes cast.
Now the reasoning for why they might allow this in the first place. Hearthstone restores a fixed amount of 1125 health REGARDLESS OF HERO LEVEL and staying within the Hall of Storms keeps restoring your health at a fixed periodic value. At early levels, simply completing the HS cast is enough to top off your hero, but as the game progresses, this method of healing becomes less effective with each increase in your health amount, meaning that at lvl 30 you have to stay in the spawn area for almost five seconds or longer to regain full strength and doing this trick will only restore the fixed amount of 1125hp where you are unlikely to continue fighting in such state.
I’m concerned more about the effect this has on completely eliminating travel time, especially in a today’s version of the game where global travel abilities (Falstad/BW/Abathur/Dehaka) were seen a problematic and were promptly nerfed.
Samuro healing up isn’t even that big of a deal because the HS cast take full 6 seconds during which you can easily destroy his images (considering they take increased damage, in a specific way) or at least gamble killing one of them hoping both of you will target the one that has a swap command queued on it which reduces his chance of success by 50% and is a valid form of counter-play. The usefulness of this trick skyrockets with certain objectives such as one on Sky Temple while it can be completely useless on other drastically smaller maps.
Honestly I would like to hear a more elegant alternative to this if someone has any good ideas, because he seems to be somewhat balanced around this trick being a thing and players who are unaware of this are playing him at a severe disadvantage. Maybe compensate him with increased/prolonged healing from globes or with a minor leech effect? Neither would significantly impact his power as he mostly shines with in overall map presence with a hit and run approach. I didn’t play him in a while and can’t tell how he feels first hand or if any of this is a valid suggestion.
Sorry for the wall of text, but there is no concise way to make sense out of this. I’m hopeful it will get some attention. The current status quo is a band-aid solution.