I followed the steps to a T just as I did last time. I used 11.0.0 (RQ2A.210305.006, Mar 2021) and 11.0.0 (RQ1A.210205.004, Feb 2021) I am not sure why it stops at 47% every time with that error. I even downloaded the rom 3 times just incase it was from that
If you are using the latest found on SourceForge (PixelDust-Eleven-aosp-coral-user-20210226-2059.zip), then you need RQ1A.210205.004 firmware. I am unsure of what you meant with the March firmware, dont use March at all, its to high of a firmware for the current ROM release. Only the RQ1A.210205.004 firmware (unless the dev says otherwise). I always use and follow what is in the METADATA file (picture shows what I mean) if unsure (or if the right firmware wasn't specified, but it is in the OP). Again, you didn't give any info of the install process used or pic(s) of the error that would help me isolate what is failing for you and where/why, so I am guessing. This is what I do (after backing up EVERYTHING on the SD and MMS/TXT):
First I set the active slot to A
Run through the firmware with -w left intact (RQ1A.210205.004)
When it wipes userdata, I get ready and as soon as it reboots, I hold the power + up volume to interrupt and enter BL
Then I set active slot to B
Run through the firmware with the -w left intact (RQ1A.210205.004)
Once the B side is completed, I let it boot, go through a quick setup and bypass everything (Google account, pin,ETC). Then I reboot to BL, set slot B active, and flash the correct boot.img (dev recommended version and found on SF), enter recovery and ADB sideload the ROM.
I do both slots so I reset all partition table layouts on both slots, and by doing both, I know if theres an issue, I can use the other slot because its fresh. You dont have to do both slots (A/B) but I do and it works for me so I offer what works and has been tested thoroughly.
It sounds like to me, your failure is in the transfer which could be ADB, ADB drivers, USB cable, or failing USB port, any one of those could cause hiccups so I would reset the device (go through stock firmware with -W), then use a different USB cable, and make sure my ADB is updated and try again.
I am not trying to be argumentative with my questions or comments (lack of info), but trying to help you so let me know how it goes and dont take me wrong please. The full path to the METADATA file is this:
ROM.zip\META-INF\com\android\metadata
*****EDIT*****
FKM just released the March update, so what I said above is void now, use the March firmware. Apologies, it was updated as I was writing my reply so follow the OP.
*****EDIT*****