Yes, some computer software only allows that. That is because of how it has been programmed.
The new Unicode specification has fileds given and given2 and each can have more than one name in each of them, with spaces between them.
So now there is the opportunity for computer systems to get the job done properly. If there does not develop a practice among people applying the specification of only using the first character of the given2 field as "middle initial" rather than using the first character of given2 and the next character after each space character in given2 to provide one or more initials after the first given name.
Not only the items that you name. Also, for example, car insurance document.
I have never had to do it, but imagine needing to produce driving licence and insurance document at a police station and them not both having identically the same name on them.
I say "I'm William Overington".
I am surprised that more males do not have three given names, with names one each from the three nearest male ancestors.
William