If the risks of a custom ROM seem too high (especially losing Widevine L1), consider a Debloated Stock ROM. Developers have created modified versions of the official Alldocube firmware that remove all the bloatware, fix the RAM management via build.prop edits, and de-Google the tablet (or keep Google apps, your choice).
This gives you 90% of the performance benefit of a custom ROM with 0% of the hardware compatibility risks. alldocube iplay 40 custom rom
Do not skip this section. Bricking an AllDocube is rare, but improper preparation causes boot loops. If the risks of a custom ROM seem
On Russian forums (4PDA) and Chinese forums, you'll find modified stock ROMs: Files to Download:
Where to find: 4PDA "AllDocube iPlay 40" thread (use Google Translate). XDA has no dedicated section.