e-utils api: get chromosome position for each snp on a gene
If your dataset is limited to human SNPs, and you know the list of SNPs, I would advise taking a look at the dedicated NCBI Variation Services.  This would be one request for each SNP, but if you fire off 1-2 per second, I think you'll be ok.
For example, for rs1490381980, you could try something like:
curl -X GET 'https://api.ncbi.nlm.nih.gov/variation/v0/refsnp/1490381980' \
   | jq '.primary_snapshot_data.placements_with_allele[] | &quot;\(.seq_id) \(.alleles[0].allele.spdi.position)&quot;'

It would be better to query for the SNP and parse the JSON in python, but jq helps provide an idea of what is possible.
Alternatively, you could download the JSON or VCF data from the NCBI dbSNP FTP site, and process out the information you need.