Enjoy your pens as you like. I have yet to try nibs bigger than medium. I look forward to that. I have recently become aware of what people are talking about with good paper. That is fun. There remain several years of learning and enjoying left for me in this pen adventure.
You need a western M really for laid or linen effect paper....an old vintage B....1/2 a width narrower than modern.....does nicely there...sort of a M-B or B-M.
I do find modern MB and Pelikan to be fatter than once....including the wider M&B nibs.
You can get a free template and print wider lines than the 'collage' used for F&EF for a M or even wider for a B....so the e is not closed. That helps when stretching one's script to wider nibs.
Some get into fountain pens with an M and go narrow, as narrow as possible. Or wide. Those who started with the economical Japanese pens, started narrow and often went narrower. So think Japanese M=western F or Japanese B=western M to be wide.
There are western B, BB....vintage German semi-flex in OB or OBB.
B is a size with pizazz.
And I've learned to like M....breaking a prejudice picked up on the com. It is smoother than an F, and not really wide.
Using MB Toffee a brown shading ink, back when I was newer.
I like shading inks.
F was light with dark trails.
M was 50-50 in shading , breaking my anti-M prejudice I picked up here on the com.
B was dark with light trails.
You see I don't buy a pen with the thought of having to sell it....and I've bought a couple Pelikan 200/215's lately in M, and am quite happy with them. M is a good width for shading, besides being a slight tad smoother than an F.
I think an M would be better than an F for glitter or sheen inks also.
Do look in Ink Reviews and check out old and new Sandy1's ink reviews. Over a time she changed the good to better papers she has used....so there are some 6 or 7 better papers that can be had if one googles.
I've been telling my self to do that....for ages.