All ironer manuals gave directions for ironing most all of Madame's wash which required ironing in those days, read most everything from linens to bras/men's shorts. It is possible to iron shirts on an ironer, but it takes skill and practice.
As for ironing creases into a shirt's yoke, many people even some commercial "hand laundries" iron shirts that way. This is especially true when shirts are ironed flat on an ironing table versus using an ironing board. My vintage Mary Proctor's book on ironing gives instructions on how to iron a shirt in 4.5 minutes, and it calls for ironing a crease into the yoke. Most men then and probably now are going to wear a jacket, so the yoke creases aren't a real bother, long as the upper front and collar (part seen when wearing a jacket)are done correctly.
Now if you really want to see a group that takes the iroining of shirts seriously, you have to check out Her Majesty's Armed Services. Royal Marines, Air Force, Naval et all are all tought at military officers college how to iron their kit up to standards, and they will be marked down if shirts are done just so. Indeed many military wives don't even bother ironing, as their husbands always complain it isn't done correctly and do it themselves,especially when it comes to their kit. Things like railroad tracks on sleeves (double crease lines) are simply not tolerated.
Ironers are great for flatwork that fits either with one go, or can be done one go on each side, or finally folded and will fit with one go. Do not think many households then had king sized sheets or the huge tablecloths we have today. When ironing multiple layers that are long, like a folded king sized sheets, it takes skill not to create "dog ears", wrinkles and creases as the layers pass under/over the ironing shoe. This is why for really large pieces I'd rather hand iron using my large ironing table. It is actually much faster and the results are spot on the first time.
L.
