Here is Delaware's rule:
Every resident and non-resident individual shall make a declaration of estimated tax for the taxable year if the tax due in excess of withholding can reasonably be expected to exceed $800.00.
https://revenuefiles.delaware.gov/2022/PIT-EST_2022-01_Instructions.pdf
PA's income tax rate is a flat 3.07%. DE's rate is graduated and can run as high as 6.60%. So there is a good chance that your "other state credit" for PA will not cover your DE tax bill.
I suggest you follow @DoninGA 's advice.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
