Alternatives would be
a) trade the pokemon individually to sysbot (via the correct games) to dump the data [will be slow and you’ll be using a public Discord, thus the owner of the server would have your data too]
b) get a hacked Switch or hack your on Swich then dump them all [relatively safe but pricey]
c) use your friend’s hacked Switch after letting them access your HOME [risk depends on the friendship]
d) let someone else access your HOME account and dump them all for you [super risky won’t recommend]
e) hire someone to do it for you, probably would require them to have access to your console or to your HOME account [probably the riskiest of them all. And pricey. And you might get scammed. Really really not recommended]
With your limitations, there’s no perfect solution and it all comes down to you. All at your own risk.
If you’re not in a hurry, and have time to spare, then do option (a). Do like 15 trades a day or something. You’ll probably get it done within half a year. Also:
(1) if caught on a Switch title, trade the Mon with the game it was caught in (origin game), to ensure the correct data was transferred.
(2) if the Mon was transferred via Bank or GO, trade via SWSH (limited to species that exists in SWSH)
(3) if the sysbot retains the HOME tracker of your Mon, can trade to the sysbot via any game