Insertions and deletions (indels) play a significant role in mammalian genomic evolution. Sensible modelling of the evolutionary process of indels is challenging and still an open research question. Several attempts have been made to explicitly model multi-character (long) indels, such as TKF92, by violating the site independence assumption and introducing fragments. However, these methods are computationally expensive. On the other hand, among the Markov-based models, the Poisson Indel Process (PIP) allows us to infer single-character indels on the phylogenetic tree, assuming site independence and distinguishing insertions from deletions. PIP's marginal likelihood computation has linear time complexity, enabling ancestral sequence reconstruction (ASR) with indels in linear time. Recently, we developed ARPIP, an ASR method using PIP, capable of inferring indel events with explicit evolutionary interpretations. Here, we investigated the effect of the single-character indel model on reconstructed ancestral sequences on both eutherian mammal orthologous sequences and simulated data. We show that our single-character indel method preserves the gap length distribution from the input alignment in the ancestral estimates. Furthermore, we confirm the well-established deletion bias. To date, ARPIP is the only ancestral reconstruction method that explicitly models insertion and deletion events over time. In conjunction with a long indel alignment, it can capture ancestral long indel events on the phylogeny.