There’s no reason to Ice Lance in the No-IL build on single target, even with Fingers of Frost, except when you’re on movement filler mode and have no means of casting anything else (eg: no Ice Floes, Orb is on cooldown as well, etc.)
The justification behind this is it’ll always be more worth it to cast something that will generate an icicle for you, as this means you get closer to launching your next Glacial Spike. Once you talent into Glacial Spike, Ice Lance falls off greatly because it has no interaction with your mastery. But your gear, corruptions, and essences (Memory of Lucid Dreams major) all tie in with your Mastery.
The thing you would want to sim is 2 target cleave, because given your gear, Azerite traits, etc. you might find it a DPS increase to use FoF-Ice Lances on 2 targets.
If you’re not into NoIL build, the only other relevant PvE build is the Frozen Orb build. This build however is even more stringent on Azerite Traits. The NoIL build basically only demands 3 x Flash Freeze, and then leaves you with wiggle room on the other traits, but the FO build needs 3 x Packed Ice, 1 x Flash Freeze, at least 1 x Whiteout, and only leaves you with freedom on the very last choice.
The FO build is more Haste centric, and very true to Frost’s “whack a proc” style. It’s mobile due to its non-reliance on Ice Floes (even though it’s still a great talent), but it shines most with RoP due to its bursty nature, and it truly excels on consistent cleave/add fights./M+ keys. It falls slightly behind the NoIL build on single target since it’s more RNG reliant and Mastery scaling on the NoIL build is just through the roof. Still, it remains competitive due to your ability to burst with the Orb in short windows, to meet DPS checks at crucial moments in fights.
If none of these builds work for you, your only other option is to play around with your talents. Frost can be very passive or very button heavy depending on your talent setup, and you’ll have to shuffle around to see what works for you. However, no other talent setup is really competitive in PvE. For casual PvE you could try something a tad bursty like Ice Nova. Comet Storm is also great when your item level is low since you can always use it with 5 Incanter’s Flow stacks given its recharge time and use your pet’s Freeze with it to get some shatter “umph” moments.