according to the Expressif doc, https://docs.espressif.com/projects/esp-idf/en/v5.3.1/esp32/api-guides/partition-tables.html#creating-custom-tables
a csv can contain spaces and short expressions, like 3M instead of 0x300000.
except that your extension no longer works in this case.

OK with :
nvs, data, nvs, 0x9000, 0x5000,
otadata, data, ota, 0xe000, 0x2000,
app0, app, ota_0, 0x10000, 0x300000,
app1, app, ota_1, 0x310000,0x300000,
spiffs, data, spiffs, 0x610000,0x9E0000,
coredump, data, coredump,0xFF0000,0x10000,

KO with :
nvs, data, nvs, 0x9000, 0x5000,
otadata, data, ota, 0xe000, 0x2000,
app0, app, ota_0, 0x10000, 3M,
app1, app, ota_1, ,3M,
spiffs, data, spiffs, ,0x9E0000,
coredump, data, coredump, ,0x10000,