For IT-242 (Conservation Easement credit) and any of the other 'not supported' forms, there are places on the Tax/Credit Wks (in forms mode) that feeds the codes on IT-201-ATT to enter an arbitrary code and amount. You don't have to do an override on IT-201-ATT.
For IT-242, enter code 302 and the amount on line 46 of the Tax/Credit Wks. This will flow to a slot on line 12 a-l on the IT-201-ATT.
You'll still need to attach the PDF of IT-242. And about 1 year in 4 they won't spot the attachment and you'll have to fix it up with a call/email to NY Tax.
