My late MIL also was a leftie forced to write right-handed; she never got good at it but somehow also never abandoned it to switch to the more dominant hand; for all her life her handwriting was just awful, and very difficult to read.
Our Aspie kid had the same issue with dysgraphia. He had real difficulty with spacing letters when he printed things; teachers were always grading him down; they said that they could not read what he had written because he scattered the letters all over the page and they couldn't put the intended words together. He was in Catholic school, however, and the style of cursive they taught was difficult for him. We bought
Handwriting Without Tears and had him learn a simpler cursive style at home, and that took care of it; suddenly the words came together properly. He was MUCH happier once he switched, and to this day, as an adult, when he has to print something on a form, it's still cursive, but with spaces between the letters.
The issue of which hand you eat with is generally not considered an issue of handedness, it's cultural etiquette. (In some countries the prohibition against eating left-handed has the force of taboo, because of traditional toileting practices.)
I'm right-handed, but my Irish immigrant parents taught us to eat left-handed, as they grew up with the Continental "fork in the left hand" style that is standard practice in Europe. American-style table settings assume that one is eating with the fork in the right hand. (The US is the only culture that does that fork-switching maneuver to allow diners to use the knife with the dominant hand when cutting meat.; which natural lefties obviously do not need to do.) The nuns at my US school (who were mostly not American-born, btw) were instructed to teach us American table manners, and insisted that we use our forks right-handed. My mother was appalled by what she saw as sloppy American table manners, and insisted that we keep our forks properly tines-down in our left hands at home. So in my family, we children all developed the habit of eating left-handed at home and right-handed in public. As an adult, I've mostly gone over to using Continental style full-time, and that is how I normally set my table if we are having a formally-set holiday dinner. However, people who meet me for the first time in a restaurant setting sometimes assume I'm left-handed, which makes my DH laugh, as he IS left-handed.
PS: Most Catholic schools used Palmer Method in the early part of the 20th century, but switched to Zaner-Bloser in the 1950s, while a method called D'Nealian was most popular in US public schools during the postwar era. This nifty chart shows a whole lot of different styles:
https://www.christianbook.com/page/homeschool/handwriting/handwriting-comparison-chart. The REALLY pretty script that you tend to see in letters written in the 19th century is Spencerian script; that was very labor-intensive to learn, and lost favor in most schools around the time of WW1.