i dont know if it is possible, but the source code of srfi-37 is available, on my machine it is at /usr/share/guile/2.2/srfi/srfi-37.scm. i didnt see an option for the "--name value" case at first glance.
apparently the --name=value syntax is to allow for long options with optional values. otherwise "--name value" and "value --name" might be ambiguous. https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html from the linked code: ;; seed - What is the seed??? seed is the initial value for what is "loads" in the code. it is the initial value for what eventually becomes the result of the call to args-fold. like the init parameter of fold.
