I wonder if there's any flying school that will do your IRT for credit against your working for them before, or even after, as an FI.
If the income and business expense cancel out and no actual payment was made, hopefully you can make it "not income" for
JS purposes, and who knows, it might also give you a chance to impress them enough that you'd pick up some subsequent remunerated instruction? It's initially low risk for them anyhow.
Admittedly doing this before Saturday seems a bit optimistic, but you can only ask (very very) nicely.
G
(Disclaimer, I only know about aviation law, maybe a little about contract law, virtually nothing about tax law.)