In addition to 5c/10c, 10c/20c also works using nickels and quarters (or it can be done with dimes and 50c chips, if so inclined). More than one way to skin the microstakes cat..05/.10 or .25/.25
.10/.25 requires a chip whose only purpose is a small blind. The dime chip becomes an indivisible nightmare.
If you are playing one game and want the buy-in to be $25-$50, I agree that I would just do 0.25/0.25.
It‘s unconventional, but if you are wanting a $10-$20, I like doing 0.10/0.10 with dimes quarters dollars, rather than nickels. If I was doing custom denominations I would do 0.10,0.20,1.00.
Having a 0.10 and a 0.20 chip with those blinds is a waste. Only 0.10s would be needed