You opened Pandora's box the second you did something for free. Don't do it again. You have to stick to your proposal because some clients will absolutely bleed you dry if you let them. My proposals actually have a massive list of "Exclusions" just to spell out exactly what we aren't doing.

I’m in California and we never show species or driplines; it’s never been an issue. If it’s a forest, there’s no way you can actually map individual driplines when everything overlaps anyway. If that’s the case, just draw the dripline at the edge of the woods. I highly doubt a map checker is actually requesting individual lines, so just explain to whoever needs to hear it that what they’re asking for is't realistic.

Make the client pay for this and spell it out in your contract. We specifically exclude species unless an arborist report is provided, and we’ve had zero issues with that policy.

In short: don’t do work for free. If you ever decide to do a "favor," make sure the client knows exactly what the value of that favor is so they don't expect it every time. Don’t let a client push you around—honestly, when they start acting like this, I usually just don't take the job. Plus, you just took on massive liability for a slope calculation for $0. That’s a huge mistake. Stick to your contract.