Yes, I’m fully aware that only four GPIOs are broken-out on an ESP-01 board.
The Tx pin is LOW for around 50ms at start-up and then it depends what you do with it after that. But, it falls into the category of “not recommended as a GPIO pin” in the table below…
and is therefore unsuitable for driving a relay, which is why I said…
In my opinion, the ESP-01 is really only useful as a WiFi modem for a non IoT enabled device, or to use in a project where physical space is at an absolute premium. However, in this scenario you probably wouldn’t have space for the 555s or relays. My go-to board is the Wemos D1 Mini, or D1 Mini Pro if an external antenna is needed. These boards are significantly smaller than the NodeMCU without the loss of any useable GOIOs.
If you want to stick with ESP8288’s then a port expander such as the MCP23017 is one option. I’ve never tried using one of these with an ESO-01, but in theory it’s possible but I prefer to use them with a D1 Mini…