Hi, 
can you explain the relationship between the VM partition settings and a custom partitions table.

I have a custom table partitions.csv in my project. 

Do the settings in VM for flash size and partition scheme apply when this is in my project?

I had them set at 16Mb and default 4Mb as I didn´t think they were relevant if I had a custom partition but when I built my code I ran out of space. The resulting build file size was per the VM partition scheme.

I changed the VM partition scheme to minimal spiffs and now my project builds, but I did not change to my partition.csv file.

The maximum size from the build output is now reported as 1966080 bytes (the 1.9Mb as per the VM setting) but my custom file sets it as 1.66Mb.

I checked in the build directory and my partitions file is there.
It seems VM does not take into account the custom file.

Here is the contents of my partitions.csv file:

# Name,   Type, SubType, Offset,  Size, Flags
nvs,      data, nvs,     0x9000,  0x5000,
otadata,  data, ota,     0xe000,  0x2000,
app0,     app,  ota_0,   0x10000, 0x1A0000,
app1,     app,  ota_1,   0x1B0000,0x1A0000,
spiffs,   data, spiffs,  0x350000,0x4B000,

I also ran the partition dump code for the ESP32 and that reports my partitions as per the custom partitions.csv file.

So it seems the code is built correctly and the partitions coincide between the partitions table and the actual built code but VM is using the values from the options to calculate the file size and not from the partitions table.

I confirmed this by changing the partition scheme back to a 4Mb scheme and the result is the following:
Program AHRS size: 1249425 bytes (used 95% of a 1310720 byte maximum) (378.80 secs)
Changing to the Minimal SPIFFS scheme the result is as follows:
Program AHRS size: 1249425 bytes (used 64% of a 1966080 byte maximum) (244.73 secs)