The whole DMR-MARC user base is now just short of 60,000 (it was well over 70k, but apparently the database admins have trimmed some data out). The BCDx36HP scanners can only support around 10k user IDs, as I've tried to jam the whole thing in before. You should trim it down based on your local area, state, or whatever, otherwise you'll still run out of room.
Greg
It's over 103,000 now
DMR-MARC admins handed over control of the database to Ham-Digital (Euro based) to not deal with GDPR issues. Ham-Digital removed Last Name, City, State/Province, and other info from it to supposedly comply with GDPR. Original DMR-MARC admin took back the database, and removed all 2xxxxx ID numbers (European ID's) and hosts it on RadioID now, leaving HamDigital to handle Euro users. This is like 40,000 or so ID's.
I have a PowerShell script I wrote that takes the two, uses RadioID data primarily since it has more data and just uses missing ID's from HamDigital. It formats it into CSV files that are for import into Anytone and TYT-MDUV380 radios, but you can use either as a source for callsign info for the SDS100.
SDS100 will only allow 1mb of data per list. For me, I just copy my state's ID's into the database, and a few other ID's that are from other sites that use the local repeaters near me.
https://www.kc1iuc.com/downloads/
PowerShell script is there, along with some recent merged CSVs