i think it's pretty clear (and has been proven a long while ago through a mod ruling after a careful examination of all the evidence....) that superman def has a form of dynamic strength. does it work in the same way hulk's does? no. i don't believe anyone has says it does. hulk (in theory) has limitless strength (proven false on panel too many times to count, of course). no one is saying (i don't think) that superman's strength is hypothetically limitless. but is it capable of increasing when extreme situations arise? obviously. denying the fact is outright trolling and should end in a ban of some sort.
is it fair to say there is a limit to what his body can metabolize? absolutely. the limit of that would depend on the writer as much as anything, but his day-to-day strength is no where near what his extreme situation strength is. he has the added drawback of imposing limits on himself, mentally, as well. this is in no way saying that his strength is greater because he stops holding back. that is entirely different. were the blocks simply mental, that case might be made. but there is a physical change taking place as well. stress leads to increased radiation absorption which leads to increased strength. in THAT way it is identical to hulk. the difference is a case can be made that he has a limit, where hulk it has been posited, does not. no ww and cap marvel and adam cannot replicate superman's strength increase. anyone gets stronger when they unleash (even humans) but their bodies don't undergo change like superman's does.
this....really isn't very complicated. /shrug