judging by how HeLa cell exists, and how telomerase activation can be permanent,
despite the issues in regulatory pathways, and its effects that may proceed to other cell types.
I don't think it's improbable to isolate a particular cell type, culture this in a lab environment and introduce the genome that is responsible for this activation. alongside monitoring regulation in cell cycling, DNA repair mechanism, apoptotic pathways, cell signalling pathways to other cells - simulating all this in computational systems biology. At least - that specific cell type, will keep this desired effect without damage to itself, locally. Unaffecting other cell types. I know telomeres can already be lengthened safely in certain specific regions.... but to have it stay this way permanently.... worthy of R&D?