should I sign out of my mi account before installing this rom?
I saw your comments in the TWRP thread, which is probably the wrong place for your questions. I have sucessfully installed xiaomi.eu rom on the second try.
I failed, when i was using firmware: lmi_eea_global_images_V12.0.2.0.QJKEUXM_20200730.0000.00_10.0_eea_7a4654b9f8
I had the same problem with rebooting to TWRP.
Then i used MiFlash2020-3-14-0 and flashed this firmware: lmi_global_images_V12.0.3.0.QJKMIXM_20200808.0000.00_10.0_global_e622045452
Afterwards i followed the instruction on OT exaxtly and flashed xiaomi.eu (xiaomi.eu_multi_HMK30Pro_V12.0.8.0.QJKCNXM_v12-10) sucessfully.
I used LRTeam TWRP also known as chinese TWRP, the 2b version.
Hope this helps you