Summary:
When rendering too many tile/block entities, the game's FPS drops, sometimes crashes. Probably, The cause is the rendering issue.

Affected Blocks:
Medium or Nearly Minimum Frame Drop :

• Bee Hive
• Beenest
• Sculk Sensor
• Calibrated Sculk Sensor
• Sculk Catalyst
• Sculk Shrieker
• Dispenser
• Furnace
• Brewing Stand
• Dropper
• Barrel
• Smoker
• Blast Furnace
• Lectern
• Chiseled Bookshelf
• Crafter‌
• Monster Spawner
• Note Block
• Jukebox
• End Portal
• Command Block (MCPE-170019)
• Jigsaw Block
• Daylight Detector
• Lodestone‌
• Suspicious Sand
• Suspicious Gravel

Serious Frame Drop:

• Signs
• Hanging Signs
• Banners
• Chest (MCPE-137537)
• Trapped Chest (MCPE-137537)
• Ender Chest (MCPE-137537)
• Hopper
• Shulker Box
• Dyed Shulker Box
• Campfire
• Soul Campfire
• Decorated Pot
• Beacon
• Piston (MCPE-157252)
• Sticky Piston (MCPE-157252)
• Enchanting Table
• Mob Head
• Structure Block
• Bed
• Cauldron

Unknown(Bug testing isn't enough or almost not possible):

• Redstone Comparator
• Flower Pot
• Item Frame‌
• Glow Item Frame‌
• Nether Reactor Core‌
• End Gateway
• Moving Piston
• Bell
• Compound Creator‌
• Element Constructor‌
• Lab Table‌
• Material Reducer‌
• Crafter
• Trial Spawner‌

Steps to Reproduce:

1. Choose one the Affected Block (The Serious category is best)
2. Place that one a lot using /fill, etc
3. See the blocks

Expected Results:
The game's FPS doesn't drop when you see the blocks

Observed Results:
When you see the blocks, the game's FPS drops, sometimes rapidly dropping it or even crashing