Yes, most 4for4 tools provide for fractional representations to cater for flex player situations. Suppose your league's starting lineup requirements are 1-QB, 2-RB, 2-WR, 1-TE, 1-WR/RB, 1-K, and 1-DST. A recommended approach would be to input these as 1-QB, 2.5-RB, 2.5-WR, 1-TE, and so on.
The numbers you enter influence the relative value of each position. If your league tends to favor WRs over RBs in the flex position, you might want to consider input variations such as: 1-QB, 2.3-RB, 2.7-WR, 1-TE.
Remember, these subtle adjustments shape the value of each position in relation to others. It's more of an art than a science and there's no definitive 'correct' answer. Experiment with different options to find the configuration that best matches your league's needs and your personal preferences. The crucial thing here is that your input numbers correctly total up to the number of roster slots.
For instance, if your starting roster includes 1-QB, 2-RB, 2-WR, 1-TE, 1-WR/TE, 1-WR/RB, a K, and a DEF, you could try: 1-QB, 2.5-RB, 3-WR, 1.5-TE. If you usually prefer WRs over TEs in the WR/TE flex, consider inputs like 3.2-WR and 1.3-TE, or other similar combinations.