It seems you're asking for a review of the running a Global ROM .
Would you like a step-by-step comparison between the Global ROM and the stock Chinese ROM for this model? Pbam00 Global Rom
First, a quick clarification: is the model number for the Oppo A5 (2020) — specifically the Chinese/Indian variant. The "Global ROM" typically means that the phone (originally sold with ColorOS in China or India) has been flashed with the international/global firmware (usually the EU, SEA, or RU version of ColorOS). It seems you're asking for a review of
If you already have a Pbam00, try debloating the stock ROM instead of flashing a Global ROM. If you want a truly stable global experience, sell the Pbam00 and buy the official Oppo A5 2020 (CPH1931) global version. Pbam00 Global Rom