I am pondering use of a slight variant of the following 6V-75V to 3.3V switching (buck) power supply:
https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=085D149D69F04A23For those of you who cannot open the above link for some reason, here is the schematic:

The application circuit will be used in 12V and 24V vehicles, hence the broad Vin range. My actual design will slightly deviate from the above design in that I will add a TVS diode on Vin to clamp spikes to 70.1V (Vc) and also have an inline Schottky diode (B2100-13-F) for reverse polarity protection (and I will use that same Schottky p/n for D1 in the above circuit as well). I will also use two 330uF 50V capacitors instead of the suggested 33uF Cin to better maintain Vin during cranking, and I will use a single 15.4uF (derated capacitance at 3.3V, originally 22uF) 10V X7R ceramic output capacitor (for greater stability over temperature) instead of the two X5R caps suggested in the above design. And I will of course have a 0.1uF ceramic cap near Vcc of my MCU and near other IC's in the circuit.
But my question centers on use of an inductive load -- specifically, a 3V relay (50mA@3.3V, with 1N4004 diode across the coil to suppress kick back). I'm not an expert on switching power supplies, hence this post. I do know that we need to keep output impedance in check with proper PCB layout techniques, and choice of the output capacitor also needs to keep impedance low as well. As such,
how negatively would my 3V relay's coil impact my 3.3V power rail? I am also thinking I should probably add a low cost
aluminum electrolytic capacitor (47uF or 100uF) near the relay coil to avoid voltage dips when the relay switches, especially because my MCU and a fingerprint sensor (with its own MCU) will also be powered on the same 3.3V output voltage rail, so any thoughts on that would also be appreciated as well.
Thank you.