Ignoring anything that just comes down to a matter of semantics and personal perference, that doesn't do much to actually answer the question at all.
Is there some specific bug with the Steam client interacting with the Head Start (forcing a redownload of the client), or isn't there? You've got mostly supposition on your end (the bolded part) that it may do it again, not that there's a guarantee that there is an issue.
If that is the problem, you (and anyone else exhibiting this issue) should probably fire off a note to both Cryptic and Steam's support teams, as this shouldn't be happening in the first place.
But, is it a continuing issue or a one-time? That's the big question I have right now (having sat through it once already). If necessary, I'll test it out myself, but I'd love to hear something more solid about this issue.
There would appear to be a bug with Steam because x,000's of players have been forced to re-download 10GB of software...(when I have a download quota of 20GB peaktime)
...Hence the desire not to take a chance. I didn't wish to use half my quota with 3 weeks to go before it would be refilled. I would have had to wait until off-peak time to download it.
You're right, there's no guarantee that it will....or that it won't....hence I do not wish to take the chance. As for whether its a continuing issue. Irrelevent for me, as Steam deleted my software and started to download the 10GB. Reading a very useful post some 8 hours later I found that I could use ShadowExplorer to restore an old copy of the game from several days ago, and so rather than downloading 10GB, I had to download about 100MB to cover the teeny patches since then. If I start that updating again...well, I'll bet you a dollar I have to download the 10GB!
Ermm...fire off a note to Crypic and Steam?...I think they know, as several thousand of their customers got scr%^&d over. I reckon one or two of them might have posted a bug message.
Good luck with finding something more solid about the issue....12 hours after the problem started there was nothing useful on the forums of either crypic or steam. Of course, there may be something there now...but I would go holding my breath for it.
Assuming someone else out of a certain portion, while fair statistical odds, isn't exactly very solid proactive behavior. :/ If everyone thought that, after all, then nothing at all would get done.
While they may be aware of the issue, letting them know the severity of it by jumping on the bandwagon would still help out. S'all I'm sayin' there.
And as a footnote, you're giving off sort of a sarcastic vibe that I'm going to assume is unintentional, specifically with the way you continue to repeat certain bits of phrasing. Or, I suppose it could also be condescending, but again.. I'm gonna hope it's just unintentional, because I tend to have similar problems myself (usually because I'm just being thorough).