As our English professor used to say, "When in doubt, leave it out," and the difference between being ambiguous 'on purpose' versus 'by accident' is one letter grade...at least.
So, in a way, you may have already answered your own question (in your footnote):
(I'm using "mind-blowing" as an adjective that is supposed to mean
Synonyms & Antonyms for mind-blowing (per Merriam-Webster; see link below):
breathtaking, charged, electric, electrifying, exciting, exhilarating,
exhilarative, galvanic, galvanizing, hair-raising, heart-stopping,
inspiring, intoxicating, mind-bending, mind-boggling, rip-roaring,
rousing, stimulating, stirring, thrilling
Therefore, it wouldn't be surprising if someone thought you meant very exciting (in some way) if the context is lacking or ambiguous.
Not at all to say that very impressive, or overwhelmingly so, isn't a well-known (albeit informal) definition of mind-blowing...
‘for a kid, Chicago was really mind-blowing’
More example sentences:
‘The maestro himself blows a mean horn with unbelievable energy and
mind-blowing skill and has the kind of stage presence so-called pop
idols cannot be taught.’
‘It is described as a mind-blowing journey into spectacular,
futuristic maze-like ‘worlds of wonder’.’
‘Support fat loss and gain more energy in the process - the benefits
of this amazing supplement are mind-blowing!’
‘There was - is - no question: Peter Jackson has roared back into
theatres with the mind-blowing Part Two of the greatest fantasy epic
in movie history.’
‘A work of cinema so visceral, so powerful, so incredibly mind-blowing
must be seen to be believed.’
‘And, then, before he knew it, another song had started up; the same
voice, the same wonderful, mind-blowing music.’
‘This record is impressive, but not mind-blowing.’
‘‘We've had more corporate donations and it's just mind-blowing the
support we've received,’ Emma continued.’
The list goes on; they give a dozen more examples for this definition (see link below).
Just FYI, this is another definition of mind-blowing (same source):
(of a drug) inducing hallucinations.
‘This teaching has warped more minds than any mind blowing drug has
‘The 1960s was the decade of mind-blowing drug experimentation.’
Curiously, this is the second meaning in Oxford Dictionaries but the first in Merriam-Webster (which states that this is the meaning of its first recorded use in 1966).
In conclusion, I would say (as our professor did)...be yourself, but know your audience. Some things are mind-blowing. That is, the word seems less informal to me when used in its proper context, as in the example sentences above (excluding the ad for the amazing supplement). That being said...not everything in the 80s was awesome (e.g. That was awesome, dude!--referring to a milkshake), so I would caution you: Mind-blowing is the new awesome...I think, so I would use it sparingly. Words like those can be addictive.