EPC did dig quite a deep shaft down the right hand side (looking down the slope). Still going, but a bit of a pain to dig. I've never looked down it to be honest. It was done in the early 2000's - but pre capping days. Could probably be sorted out and pushed on down.
Also - EPC had another little tat recently at the bottom of the slope in the centre. Went down about 2 meters to a solid floor.
First job that needs doing before any serious dig is attempted would be to dig a decent and stable shaft down and under the main arch through to the main chamber. The current crawl is a horrible little grovel past broken glass ,rotten tin sheet and what ever other dead things have found their way down there :yucky: