How does android adjust the size of System. img to support multiple built-in applications?

Open in excel:
Alps/mediatek/build/tools/ptgen/partition_table.xls, The MT6573 no sub-table in the table,
Modify 11 rows/G Columns
For example, the default 11 rows:
11 ANDROID YAFFS2 1500000 DD00000 200 MB 204800 209715200 C800000 1
You can see that the 11/G column is 204800 = 200*1024. You can change it to 256*1024,280*1024, change 200 MB to 256 MB, and save it, excel automatically calculates the size of other zones.
The actual F column is only used for viewing and has no practical significance.
In principle, the size of system. img should not exceed half of the total storage size. Such as 512 M storage, do not exceed 256 M.