Most developers are fixing bugs, helping sales, keeping systems online, keeping up to date on patches, performing security scans, complying to some internal policies.
https://www.law.cornell.edu/uscode/text/26/174
> (3)Software development For purposes of this section, any amount paid or incurred in connection with the development of any software shall be treated as a research or experimental expenditure.
I mean, this probably still matters a lot for startups given their shorter lifetimes, but it seems any large company(I'm thinking of, e.g. Apple, who has plenty of cash on hand) that's been around for a while could just wait it out? I am not familiar with corporate tax law and how deals are structured, but could you also defer revenue in the same way to offset(e.g. customers with a 5 year contract paying progressively more but keeping the same total $ amount to sync with your deductions)?