Surprised SLC is using unadjusted EBITDA as its primary earnings...

Surprised SLC is using unadjusted EBITDA as its primary earnings measure, given how EBITDA treats IRUs.

IRUs (long term agreements for network access and use) are paid upfront and go through the P&L over their life. If you sell an IRU you recognise the revenue over the life of the contract. If you buy an IRU you amortise the cost over the life of the contract.
SLC buys and sells IRUs, so it is recognising IRU revenue and amortising IRU costs over the life of the agreements.

The key here is that EBITDA provides an incomplete view of IRU revenue/expenses. EBITDA includes IRU revenue but excludes IRU costs (the IRU amortisation charge is self-evidently below the EBITDA line).

My view is that investors should adjust EBITDA so that IRU revenue and expenses are treated the same way. If you want to treat IRU's as a capital item, you should remove deferred IRU revenue from EBITDA. Alternatively, if you want to treat it as an expense, you should include the IRU amortisation charge in EBITDA.

If you do this you'll find FY19 EBITDA halves.