Connect on your phone or other device. Connect to travel router. Clone the mac address of your device. Connect router to wifi. Adjust device to not auto login. Good to go.
This is just flat-out untrue, OIDC or SAML plus SCIM should be the default for any enterprise-focused service provider or "you're doing it wrong". You can offer your own IDP as the default, but all of the problems that need to be solved to allow your customers to configure their own IDP are important to the design/architecture of your service and the only reason these providers are treating it as special is because they didn't build the integration between their service and their IDP correctly the first time. Provisioning and authentication are critical to security and you're actively harming your customers if you require them to use your own IDP solution in order to use your service.
It's really fun when your ISP starts using CG-NAT as a security feature in marketing. You ask them for a static IP and they have you sign an agreement that you won't be getting the BENEFITS of their CUSTOMER FIREWALL. Yeah ok, so if that's the language around this then we're just screwed aren't we? And you also can't tell me when you're planning to support IPv6 of course.
Remember even if timestamps may be generated using a monotonically increasing value that does not mean they were committed in the same order to the database. It is an entirely separate problem if you are trying to actually determine what rows are "new" versus "previously seen" for things like cursor-based APIs and background job processing. This problem exists even with things like a serial/autoincrement primary key.
I'm a huge proponent of using SQLite as an abstraction over a filesystem. One warning I will note though, is be aware that a SQLite database does not shrink unless you vacuum it (basically copies the data into a separate file and deletes the original). This is a manual operation you have to do at points where it makes sense within your application. So be careful with disk usage when just writing binary data and then deleting it.