hAP AC3, what am I missing

Not able to get this device flashed, either through physical reset or try-ethernet-once-than-nand options using windows.

RouterOS 6.47.8, connected via switch as documented.
-Renamed the initramfs-kernel file to rb.elf.  rb.elf copied into the files folder
-rfc951=1 added to config.ini (complete file below)
-tiny pxe configured per install documentation

"Continue holding the reset button until you see TFTPd: DoReadFile: rb.elf in the Tiny PXE log window."
   I see communication with the device during this process, but never see TFTPd: DoReadFile:, even holding the reset button for around 1 minute.
   with the try-ethernet-once-than-nand technique, I see communication, but never see any read for over 30 minutes. 
      never see the device reboot
      after hard reboot, hAP comes up in factory configuration.

Have gone through multiple iterations of this.  How long does the upload take?  Am I missing something?

tiny pxe config.ini.  Do I need to hard code the full path to the rb.elf?
                 ;needed to tell TFTPd where is the root folder
                 root=files
                 ;bootp filename as in http://tools.ietf.org/html/rfc951
                 ;filename=ipxe-undionly.kpxe
                 filename=rb.elf

Complete config.inf

[arch]
;will over rule the bootp filename or opt67 if the client arch matches one of the below
;00006=bootia32.efi
;00007=bootx64.efi
;00009=bootx64.efi
[dhcp]
rfc951=1
;below is applicable only if proxydhcp=0
;rfc951=1
;needed to tell TFTPd where is the root folder
root=files
;bootp filename as in http://tools.ietf.org/html/rfc951
;filename=ipxe-undionly.kpxe
filename=rb.elf
;alternative bootp filename if request comes from ipxe or gpxe
altfilename=menu.ipxe
;start HTTPd
httpd=1
binl=0
start=0
dnsd=0
;if you have a dhcp server on your lan, set proxydhcp=1
proxydhcp=0
;default=1
bind=1
;tftpd=1 by default
;will share (netbios) the root folder as PXE
smb=0
;will log to log.txt
log=0
;opt1=
;opt3=
;opt6=
;opt28=
;opt15=
;opt17=
;opt43=
;opt51=
opt54=192.168.1.10
;opt67=
;opt66=
;opt252=
;poolstart=
;poolsize=
;alternative bootp filename if request comes thru proxydhcp (udp:4011)
;proxybootfilename=
;any extra dhcp options
;my gpxe / ipxe dhcp options
optextra=175.6.1.1.1.8.1.1
;the below will be executed when clicking on the online button
;online=online.bat
;offline=offline.bat
;if log=1, will log to log.txt - not recommended, rather, use the syslog feature
log=0
;syslog=127.0.0.1
[web]
port=80
;php.exe file.php param1=value1
;download php from https://windows.php.net/downloads/releases/
;php-5.6.38-nts-Win32-VC11-x86 tested with success
php=c:\php\php.exe
;cscript.exe file.vbs param1=value1 //nologo
vbs=C:\Windows\System32\cscript.exe
js=C:\Windows\System32\cscript.exe
;python.exe file.py param1=value1
py=C:\Python27\python.exe
ps1=C:\Windows\System32\WindowsPowershell\v1.0\powershell.exe
;the below will be used if you turn on dnsd
;[mydomain.fr]
;ip=10.0.0.254
;[10.0.0.253]
;host=mydomain2.fr
;[frmDHCPServer]
;top=412
;left=768
[frmDHCPServer]
top=184
left=757