Is there any way to align ChIP-seq reads to telomeres?
This paper https://www.biorxiv.org/content/10.1101/728519v1.full examines the mapping of some human telomeric sequences, and indicates that there is something like 130kb missing at the telomeres in the HG38 assembly.  One option might be to take the HG38 assembly, and add some missing telomere sequences as an additional pseudochromosome to the FASTA file.  Then if you used this modified reference to align your reads, you should soon get a feel for the level of telomeric reads in your data set.