The important thing is to keep the F-plan sequenced so that it is giving you accurate distance-to-go. That is useful information.
If you think you need SPDBK, you need it. I don't bother with trying to calculate the required VS in such circumstances. Just use the SPDBK until current altitude + 1000ft (to allow for deceleration from 250kts) x 3 = track miles to go. If it's not working, get speed below 250 and drop the gear. Don't worry about finesse, fix it quickly. I use a "gate": On glide at GRN DOT with gear down by 2000ft above TDZ, decelerating and configuring. If there's a tailwind and EAI is on, make that 2500ft. If I don't make this gate I'm probably going around.
It's better not to accept the short cut and tell them how many miles you want.
HTH,
WS