When is the line crossed into "gold-digging" when it comes to practical stuff instead of luxuries?

As the title asks, if you begin to date a single man and there's a large income gap, what kind of financially-adjacent actions do you think are reasonable to expect as part of the normal dating process, without coming across as a "gold-digger?" This could be anything from paying for dinner on the first date, to having a shared home and bank account as a married couple.

Background on me: I'm quite short (5'4" if I haven't had a haircut in a while). But I also make $350k+ a year as a physician. I generally otherwise pass the "fit and handsome looking nice guy with a good personality, respectable job and plenty of friends" test, but I'm not going to lie to myself and deny that the Desirabilty of Short Guys is Dependent on Income. I'm on the playing field (at least when blasted minimum height filter apps aren't in play), but those financial implications can't be ignored in favor of just looking at utopian love ideals.

My five-plus year serious relationship (including engagement) ended with infidelity, and I'm planning to get back out there. There are plenty of good dating candidates, but in my small town there will be a significant income gap no matter who I go out with...I'm ok acknowledging that, and acknowledging that it means that I'm going to have to foot the bill for joint activities that they wouldn't otherwise be able to afford (certain restaurants, trips, etc). I'm also the type of guy that would spend his last dollar and last ounce of strength helping someone, wants to make life better for a partner (and their kids) and in the long term am very much a "what's mine is ours" guy. This has, unfortunately, come back to bite me in previous relationships and I've been taken advantage of (in the sense that a financial action solely benefits my partner, at my expense)...and want to nip it in the bud this time around.

The twist is that the exploitation hasn't generally been with things like classic lifestyle creep with luxuries (I'm not really a flashy guy, nor have been my partners); instead it's been with costly quality practical things ("sure, I'll pay for the top tier of little Johnny's ACT review course and get you a new vehicle that's safer than your old one...you're only asking for a boring Toyota over a Mercedes, so that seems entirely reasonable!"). That has made it difficult to determine if something is inappropriate or not (versus, say, being begged for a luxury purse) until it's too late... I NEVER use finances to belittle or control a partner, and in many cases it's been more a case of poor fiscal literacy instead of a deliberate attempt to milk me for all I'm worth ...But in most cases it's been "I SHOULD have to pay for stuff because I CAN pay for stuff easier."

What's a normal and reasonable expectation if you're with a guy with a large income gap? Assume that you're financially stable on your own while single, but definitely want to move towards cohabitation and true partnership (no codependent behaviors). Where do you think those expectations cross into red flags for "gold digging," especially when it comes to practical stuff and how would I identify them/address those flags? Any advice as to establishing boundaries and expectations early in the relationship without turning them off or making them feel like they're being controlled?