Instead of hacking the textures, learn the terrain generation. In Bloxd.io, diamonds spawn at specific Y-levels (heights). Use the coordinates (F3-style debug is sometimes available) to mine at the optimal level. Branch mining at Y=11 is statistically better than any X-Ray pack.
You may have copied a "full transparent" pack by mistake. Make sure the pack you choose specifically outlines or highlights ores while only blanking out stone and dirt. Conclusion bloxd xray texture pack