Keep daydream even when not charging

I'm using an old Wileyfox Swift as bedside clock, with FsClock-Android running as DayDream service showing the time. To give the battery a long life, I prevent it from charging more than 80% via Battery Charge Limit . Unfortunately the display (and thus the clock) is turned off when the battery is charged to 80% and the charge limit app stops charging. How can I keep the display (and DreamService) on even if the battery is not charging anymore? ---- The phone runs LineageOS 17.1 (Android 10), rooted with Magisk.