You don't have to use the funding goals. One option I like to use for things that are budgeted each check is to use the notes section instead (eg "$200 per paycheck").

> So if I create a “target balance by date (a year away for the full expected cost of optometry) and then start dipping into that budget throughout YNAB will start telling me I need to put away more. But I don’t, these costs are planned to go down.

If the amount of money that you want to have by that target date is less than your target goal, then it's probably not a good approach for you. One option may be to instead divide the total amount you plan on spending between now and then and create a monthly goal instead.

> So I created a spreadsheet. But it feels so manual.

IMHO manual is good - that means you are aware of what's happening. I used a supplemental spreadsheet to figure out how to get started with allocating my money and I still refer to it when I get a paycheck. For example, I use it to tell me how much of my check I need to allocate to bills so I don't fall behind (I just assume 2 biweekly checks per month and treat the occasional third as a "bonus"). YNAB just provides the digital envelope tool, it doesn't tell you where to put your money.

> If I create a monthly funding goal I’ll have to manually divide the amount YNAB is telling me I need to fund for each category to input my budget.

Do you really need to divide every category evenly with every check? I only have a few categories that I actually use throughout the month (groceries, gas, dining out). For those I usually budget some amount of each check, but for the other categories I usually budget the full monthly amount and just keep going until the check runs out (usually in order of when I will need the money). Whatever didn't get funded is funded with later checks. If I end up needing to adjust something, then I do that as needed.