If anyone is interested, I heard back from Mares.
Mares response "If the computer stays in a sealed compartment it will not sense the ambient pressure, so it could cause an error on pressure measurement."
I followed up and asked about storage in a dive mask box for a couple of days with the battery installed while travelling between locations, and also about longer term storage in a mask box, with the battery removed but stored in the same mask box as the computer.
Mares response from an engineer in Italy, "I think the procedure followed by the customer is ok, I don't foresee risks"
They had no response as to why different computers may not have the same instructions about storage in a sealed box (understandably).
Regarding different computers on this issue, as far as I could see:
With such a warning: Mares Nemo Wide, Mares Quad, Mares Icon HD, Mares Icon, Mares Genius, Galileo Sol, Galileo G2
No such warning that I could see: Perdix, Petrel, Aeris A300CS, Suunto D9, Kaon, Oceanic DC101
Note about Mares manuals (English language): It looks like they changed their format for the manuals sometime between 2009 and 2012, and started using the title Instruction Manual rather than Owner's Guide. Also, it seems that around this time they started putting in the warning about sealed containers. So older manuals for the same computer may not have the warning. (Not exact, since they seem to have had a bit of a transition period between the formats)
And yes, I do have a bit of time on my hands, why do you ask?
Mares response "If the computer stays in a sealed compartment it will not sense the ambient pressure, so it could cause an error on pressure measurement."
I followed up and asked about storage in a dive mask box for a couple of days with the battery installed while travelling between locations, and also about longer term storage in a mask box, with the battery removed but stored in the same mask box as the computer.
Mares response from an engineer in Italy, "I think the procedure followed by the customer is ok, I don't foresee risks"
They had no response as to why different computers may not have the same instructions about storage in a sealed box (understandably).
Regarding different computers on this issue, as far as I could see:
With such a warning: Mares Nemo Wide, Mares Quad, Mares Icon HD, Mares Icon, Mares Genius, Galileo Sol, Galileo G2
No such warning that I could see: Perdix, Petrel, Aeris A300CS, Suunto D9, Kaon, Oceanic DC101
Note about Mares manuals (English language): It looks like they changed their format for the manuals sometime between 2009 and 2012, and started using the title Instruction Manual rather than Owner's Guide. Also, it seems that around this time they started putting in the warning about sealed containers. So older manuals for the same computer may not have the warning. (Not exact, since they seem to have had a bit of a transition period between the formats)
And yes, I do have a bit of time on my hands, why do you ask?