We dropped Gmail OAuth because we couldn't afford Google's security review. Is email forwarding a dealbreaker for you?

Hey IH,
We're building feedimmo, a feed that aggregates property alerts from portals like SeLoger, Idealista, and PAP, scores each listing against your criteria, and surfaces the ones worth looking at. Built for expats and anyone searching across borders, where you're typically juggling three or four portals at once and getting buried in alerts.
The core of the product is inbox connection. To aggregate your alerts, we need access to the emails the portals send you. The obvious approach is Gmail OAuth: connect once, we monitor your inbox. We built it. Then we hit Google's CASA Tier 2 security assessment, which is required for apps that access Gmail data. It's not a technical barrier, it's a budget one: the audit costs thousands and we're pre-revenue. We pulled the OAuth flow and went with email forwarding instead.
The way it works now: each user gets a unique forwarding address (listings.xxxx@inbox.feedimmo.com). You set up a Gmail filter that forwards portal alert emails to that address. We provide the filter as a downloadable XML file. One import in Gmail settings and it's done. Or you can forward emails manually, one at a time, which takes longer but requires no setup.
It works. But I genuinely don't know if "download this XML and import it in Gmail" is fine for most people or a drop-off point.
So the question: if you were searching for property and came across this tool, would the forwarding setup stop you? And if you've built around similar API cost constraints, curious how you handled it. The product is at feedimmo.com if you want to see the flow firsthand

thanks a lot!!