Can these new etymological pairs of PIE roots be true?

Question

I find a paper containing new lists of cognates on PIE root level, and don't know such phenomena or rules are convincing or not, the list follows below:

1. The voiceless stop vs. voiced aspirated stop alternation3

1.1. *dʰrei̯k(ʰ)- vs. *dʰrei̯gʰ-: ‘hair, bristle’

1.2. *h₁eḱ(s)- vs. *h₁eǵʰ(s)-: ‘out’

1.3. *(h₂)kou̯s- vs. *gʰou̯s-: ‘hear, sound’

1.4. **h₁reu̯t- vs. *h₁reu̯dʰ-: ‘red’

1.5. *ḱ(e)rd- vs. *ǵʰ(e)rd-: ‘heart’

1.6. *kap- vs. *gʰabʰ-: ‘grab, take’

1.7. *kaput- vs. *k(a)ubʰut-: ‘head’

1.8. *ḱel-1 vs. *ǵʰel(h₂)-/*gʰel-1: ‘warm, bright, shine, yellow, green, blue, sun’

1.9. *ḱelb- vs. *ǵʰelb-/gʰelb-: ‘help’

1.10. *ḱer-2 vs. *gʰer-: ‘grow’

1.11 . *ḱe-/*ḱo- vs. *gʰe-/*gʰo-: ‘this, that’

1.12. *ko(m)- vs. **gʰo(m)-: ‘with, together’

1.13. *lei̯p-1 vs. *Hlei̯bʰ-: ‘smear, stick’

1.14. *lei̯t-1, *lei̯t(ʰ)-29 vs. *lai̯dʰ-: ‘be disgusted, suffer, hurt’

1.15. *lento-12 vs. *lendʰ-1: ‘flexible, fluid’

1.16. *mei̯k- vs. *mei̯gʰ-: ‘close the eyes’

1.17. *n̥ter- vs. *n̥dʰer-: ‘under, below’

1.18. *pel-9 vs. *bʰel-1: ‘white, shine, burn’

1.19. *per-2/*per-2B vs. *bʰer-1: ‘over, go over, carry over’

1.20. *pleu̯- vs. *bʰleu̯-: ‘run, flow, swim’

1.21 . *pleu̯k- vs. **pleu̯gʰ-: ‘fly’

1.22. *plou̯- vs. *b(ʰ)lou̯-: ‘flea’

1.23. *rep- vs. *rebʰ-: ‘grab, rip out, be taken, be furious’

1.24. *sek-2, *skei̯- vs. *segʰ-, **sgʰei̯-: ‘cut, separate’

1.25. *(s)keu̯p- vs. *(s)keu̯b(ʰ)-: ‘bundle, flock’

1.26. *telek- vs. *teleǵʰ-13: ‘hit’

1.27. *ters- vs. *dʰer-2: ‘dry’

1.28. *-tlom vs. *-dʰlom, *-trom vs. *-dʰrom: instrumental suffixes

1.29. *tragʰ- vs. *dʰ(e)ragʰ-: ‘pull, bring’

1.30. *u̯ekʷ- vs. *u̯egʷʰ-: ‘speak, speak solemnly’

2. The *l/*n alternation

2.1. *al-1, *ol- vs. *an-2, *on-: ‘this, that’

2.2. *mel-4 vs. *men(e)gʰ-: ‘much’

2.3. *pleu̯- vs. *pneu̯-: ‘flow, blow’

2.4. *-sleh₂ vs. *-sneh₂: object indicative suffixes

2.5. *su̯el- vs. *su̯en-: ‘sun’

2.6. *u̯el-2 vs. *u̯en-1/*u̯enH-: ‘want, love’

2.7. *u̯el-8 vs. *u̯en-2: ‘hurt, hit’

3. Co-occurrence of both alternations

3.1. *gal-2 vs. *gʰel- vs. *kel-6 vs. *kan-/*ḱan-: ‘call, cry, sing’

The data is from "Consonantal Alternations in Indo-European Roots: Diatopic and/or Diachronic Variants or Functional Mechanism?", published by "Journal of Indo-European Studies The 45 Vol., 2017"

Answer 1

Possibly but we're delving here into the language that went before proto-Indo-European. The alternations are ones found in other languages. For example the l/n alternation is found in Ancient Egyptian and the k/gh is reminiscent (although different) to Verner's alternations in Germanic, so the theory is not far-fetched. There may be the relic of the l/n alternation in Germanic in the word for 'sun' (English 'sun' but Gothic 'sauil'), which indicates there may have still been an l/n grammatical alternation in proto-germanic. Given the number of pairs found by Bizzocchi it looks likely and I'm sure that many theories can be built around this evidence.