If you are going to visit Ziemia Kłodzka - I strongly recommend Singletrack Glacensis. One of the biggest singletrack systems in Europe (200 km), brand new, great condition, accessible for every rider with minimum MTB experience. My picks (assuming you are relatively new to MTB) would be: Ostoja (Masyw Śnieżnika) , Jagodna (Góry Bystrzyckie) or Brzozowie - all loops there except Everest which requires some skill (Góry Stołowe). If you prefer something closer to Góry Sowie try Łaszczowa (impressive altitude gain, perfect for e-bike).
If you have real MTB skill you can try Wilcza or even Enduro Trails in Srebrna Góra (for beginners/medium skilled riders: Polak Potrafi - uphill MTB trail perfect for e-MTB, Romet D-Line - to go down, some skill required). Other trails in Srebrna Góra require
real enduro skills.
Being in this area and not trying Singletracks Glacensis would be the biggest mistake imaginable for e-biker. Try just one and you will immediately like to ride them all.
Link
I will be riding in this area 19-24/07 (on the pictures - not me - the guy behind this system)...
Góry Sowie - not so special. Don't miss Góry Stołowe, they are unique. If you want easy ride (with one steep climb - ca. 200m horizontally, nothing to be worried about) around them try (marked bike paths):
If you plan well, you will not need a spare battery for a day trip. Using standard mode I'm able to ride 50km on 500Wh battery no matter the altitude gain. The trip on the map above requires much less. On Glacensis you can plan to leave your car with spare battery on the forest parking on the intersection of the loops and execute 8-pattern. Check Mapy.cz app with the option for automated MTB routing.