Under TPS EAD you can work for any employer. On OPT ead you can work for any employer - only thing is that you and your employer need to report to Dhs/uscis about you being in your field of study and both the employer-employee are benefiting.
There is no restrictions on who you can work with using f1 opt ead. The policy is just being tighter because most south east asian consultancies exploited f1 students and existing rules set by dhs.
But, everyone needs to earn, eat and sleep. I see lots of american people (my friends) making career changes; someone even dramatic ones. F1 students jumping to IT based jobs isn't anything more than a career change - the problem was exploitation. The exploitation by cunning stake holders is what is make life harder for new graduates. If your employer is willing to support you and justify you role in the company in the light of what you learned in your school - It's no big deal.
My main degree is biology, but dominant role in my graduate degree was bioinformatics even with python programming and data science - so I can fit pretty much anywhere between IT and core biology. All I need is to justify and also show my employer that I can handle the given work on spot if not by teamwork or by taking sometime to update myself.
