As mount technology has advanced, new mounts are appearing with encoders and closed-loop motion servos which eliminate things like periodic error and other pointing and tracking errors. When combined with a high-quality flexure model (TPoint, PointXP, APCC), the result is a mount that will point to within a handful of arc seconds all-sky. Examples are the Sidereal Technology control systems, PlaneWave's STI as used with their Ascension and other mounts, and the Astro-Physics Command Center. These systems typically require some sort of initialization at the beginning of the night, including a "find-home" and/or a single sync against the sky, to establish their best accuracy.
ACP has a "single sync" mode for these types of systems. After each time ACP is connected to the telescope, as observing is done, only the first pointing update will cause a sync to be sent to the telescope. This is provided as an automated alternative to the manual "first-sync" procedure that these types of mounts usually provide. ACP needs to support ACP Expert, which is a 24x7 hands-off system, so ACP needs to be able to start these types of mounts up hands off. Single sync works by making ACP and other software see the scope as one that cannot be synced after the first sync is completed. Thus, as ACP starts observing at the beginning of the night, the first pointing update results in a sync being sent to the mount, making it point to its best accuracy. Thereafter, ACP makes the scope look like it cannot be synced. Therefore ACP's observing logic treats the scope thereafter as one that cannot be synced, and instead adjusts its pointing as needed. For these excellent scopes, "as needed" usually translates into "no adjusting needed".
If your mount has encoders, and if it truly points well enough that it doesn't need pointing updates, and if your rotator doesn't slip or cog throughout the night) then you can try using the single sync mode.
Note that with Single-Sync, subsequent pointing updates will not re-sync your system. They will jog the telescope so that the upcoming data image will be centered. Since only a mis-centered data image will trigger that pointing update (on the next target), you really have to depend on your scope to perform like it's supposed to. If it doesn't you'll see a pattern of slew, image, note pointing error, request pointing update, slew, pointing update, correction jog, image, within pointing limit, slew, image, note pointing error, etc. etc. alternating between doing and not doing a pointing update on each subsequent target. This is an indication that you may need to either relax your Max pointing error or go back to using pointing updates on each target to center out the pointing error before acquiring the data image (reduce Max slew w/o pointing update to 0 since you can't sync).
One last thing: pointing updates are also used to translate between the mechanical angle of your rotator and the sky position angle, which must be accurate for guiding. If your rotator slips, cogs, or has other dynamic accuracy problems, you'll have to rely on the pointing updates to take out these errors or you have a high risk of failing to acquire a guide star per the FOVI line-up you used to determine the PA coordinate for your target.