Abundance ratio of iCOMs with respect to CH₃OH in HOPS-108 compared to other isolated hot corinos. The sources are separated according to their class, with no particular order within a given class. The open symbols correspond to the sources where the CH₃OH column density is most likely underestimated due to its high optical depth (See Sect. 4.2.1). The Class 0 sources are: IRAS 2A, IRAS 4A2 (Taquet et al. 2015; López-Sepulcre et al. 2017), B1-c, S68N (van Gelder et al. 2020; Nazari et al. 2021), IRAS19347 + 0727 in B335 (Imai et al. 2016), HH212 (Bianchi et al. 2017; Lee et al. 2019), L483 (Jacobsen et al. 2019), Ser-emb 1 (Bergner et al. 2019), IRAS 16293 A (Manigand et al. 2020; Calcutt et al. 2018), IRAS 16293 B (Jørgensen et al. 2016, 2018; Lykke et al. 2017; Calcutt et al. 2018), HOPS-108 in OMC-2 FIR 4 (this work), and the sources from the PEACHES survey (Yang et al. 2021), including Per-emb 1, Per-emb 2, Per-emb 5, Per-emb 10, Per-emb 11A, Per-emb 11C, Per-emb 12, Per-emb 13, Per-emb 18, Per-emb 20, Per-emb 21, Per-emb 22A, Per-emb 22B, Per-emb 26, Per-emb 27, Per-emb 29, Per-emb 33A, L1448 IRS3A, L1448-NW, SVS-13B, and B1-bS. The Class I sources are: Ser-emb 17 (Bergner et al. 2019), L1551 (Bianchi et al. 2020), and also sources from the PEACHES survey (Yang et al. 2021), including Per-emb 35A, Per-emb 35B, Per-emb 42, Per-emb 44, Per-emb 53, and SVS13-A2. The same plots for HCOOCH₃ and CH₂DOH are represented in Figs. 4 and 6, respectively.